Seems like it's getting common to say Maj has low durability because one time he went to the sun with protection and some characters have knocked him around. I disagree with this assessment so I'm just saving one of my posts where I responded to it here so I know where to find it in the future.
In one instance when he goes into the sun for weeks on end he protects himself. In another, when he's not there for long, he is unprotected. He's also shown the durability to fly around stars, take nukes to the face, fly into a planet-sized object at FTL speeds (which provoked only an "ouch"), remain unharmed though being inches away from multiple multi-thousand megaton explosions (and trade blows with a character that could be hit directly with the same force multiple times), resist the forces exerted on his body when moving planets, literally shrug off magical assaults that would topple giants, resist the applied force of a being that smacked down Superman (when Supes had backup that was on his level of strength and durability), take hits from a character that has displayed the ability to shatter the moon (and casually toss asteroids and go literally head to head, as in flying at it at full speed, with a being bigger than a planet), withstand an explosion powerful enough to at least break the earth and moon and at most destroy the planet entirely, and survive in Otherspace unharmed (multiple times). If you cancel out the sun thing (since he displayed the durability to withstand the sun later on when he turned a star ingot into a star hot and bright enough to stand in for the sun - he actually had to put in dampeners too so it might have been producing more energy - and sustain life on Earth and then moved it without protection) the rest of the feats paint a pretty nice picture. You can average it in and that one thing (which isnt even a bad showing) doesn't bring down his other feats of durability. You're trying to say his durability isn't all that but when you look at a good list of his durability feats, he's solid.
That didn't include anything about other characters he fought so I'll just say that Spartan and Maul, the two characters most often brought up, are a lot stronger than people give them credit for. Spartan's power levels were raised to Majestic's level (the body with the Void's power was clearly superior to his other bodies that Majestic was going through like Wolverine goes through ninjas and girls) and when they fought Majestic was dying anyway. Maul can easily put more mass in one fist than an aircraft carrier, which is nearly 100,000 tons (more than even many top tier Marvel characters can lift) and still retain plenty of intelligence. If he sacrifices some smarts, that number skyrockets, and that's just one fist. Maul has also beaten Captain Atom (someone approaching Superman's durability) so hard he literally couldn't think straight. Maul hitting someone is not a joke. However, Majestic has taken a full on hit from Maul directly to the face and was not only unmoved, but responded by tossing him away after telling him he wasn't good enough. He's also knocked a decently sized Maul (bigger than the time when one of his fists had the mass of an aircraft carrier) across a room in the middle of a fight. And the fight that people usually bring up to say Maj couldn't beat Maul was in Majestic's first appearance and it wasn't like he lost the fight. Maj would hit Maul and then Maul would grow bigger and stronger to take it and then Maj would hit him harder. The fact that he was able to hit harder each time means that he wasn't hitting his hardest at any point. He was trying to knock him out, not kill him, and Maul's power allows him to take tons of physical damage. Majestic has also traded blows with a clone of the High, who was strong enough to crack the moon in half.
As for claims of him losing to no-name characters like Crusade I think it's silly for two reasons. First, just because a characters doesn't have a fleshed out history doesn't mean they're weak. There's no reason to assume that just because a character is new they must be weak and so losing to them means the main character is weak. In fact, it's most often the opposite. The new carrier is being put on the main character's level by showing up and knocking them around. It's the way to establish their strength, not lower the main character's. But that's just in general. The other reason it's silly is specifically because of the character Crusade. Crusade got power from the enemies he fought. If he wasn't already on Majestic's level, just fighting him (and Union and Spartan and Maul all at the same time) the strength he was getting would put him there. Also worth mentioning is that at one point during the fight after Crusade seems to have downed Majestic, Crusade says that they're both weary and they have to finish the fight (What?! Just because someone is down doesn't mean the fight is over? Remember this for when we get to Captain Atom...) and they haven't figured out who the winner is yet. Majestic isn't weak, Crusade is just awesome. Too bad he never came back.
Yes, there are times where things not on planet-destroying level have hurt Majestic, but that doesn't set the bar for his durability, and is no different than Flash being hit by people not moving at lightspeed, Wonder Woman being hit by people who aren't on the top tier in fighting skill, and Superman getting hurt by attacks from people who aren't on his level. Majestic shows high durability more consistently than low durability and him not being truly invulnerable and going through the same highs and lows that every character goes through doesn't make him low on the durability scale.
Should also add the Captain Atom thing since that gets brought up a ton too, even though it's not just a durability thing. Creator and Static rebut this better than I do, but it's pretty simple. The claim is that because Captain Atom said Maj isn't as strong as Superman and that Captain Atom beat him in their first fight, Captain Atom is superior to him and Superman is too. However:
1) Captain Atom has not been in a real (or any, according to Static I believe) fight with Superman. This means his claims about Majestic's strength can be thrown out.
2) Captain Atom looks up to Superman in a major way (again according to Static, Atom is a Supes fanboy) so even if his claims hadn't been thrown out, they'd be questionable.
3) Gauging strength while getting punched in the face isn't an exact science. Even if Atom got hit by both of them back to back, it wouldn't be an accurate judgement. So there again, Captain Atom's claims are questionable. (Spider-Man has said that Morlun (not a 100 tonner) hits harder than the Hulk (way past 100 tons). This isn't rocket surgery.)
-That should cover Atom saying Supes is stronger, but how about the fact that Atom beat Majestic?
1) Majestic claims that he wasn't trying to kill Atom. This is iffy since he seems pretty serious about hurting him despite what he says later, so you can take that as you will.
2) Atom left before the fight was over. He stunned Majestic with a big blast, knocked him into the ground then flew away. I'm not saying he didn't leave that confrontation on top, but it's not like Majestic was out of the fight. Getting knocked around doesn't mean you lose a fight every time.
3) Majestic is clearly superior in every interaction after that. Atom tries flying as fast as he can to escape the WSU and Maj passes him and basically pulls him over for speeding. An enraged Atom tries to punch Maj out of the sky and Maj stops it with an open palm. Atom keeps trying to fight Maj (who this time isn't fighting back and says he just wants to talk) and Maj takes his hits and holds him by the neck. Maj only ever makes one offensive move (throwing Atom through the Washington Monument) after Atom spits on him and even then he says it's just to get his attention. Atom may have gotten a good hit when Maj first met him, but later, Calm Maj > Angry Atom (who knew what he was up against).
4) There's also the matter of Atom having a shard of the Void lodged in him. Everyone else who has had the power of Void (or exposure to any of the orbs of power like the one that made the first Void) has had a major power upgrade. Why assume Atom didn't get one as well with his fancy new costume?
5) Atom isn't really inferior to Supes. This isn't something I've verified myself, just seen supported in various places and in various ways, but it appears that Atom really using his powers is superior to Supes, so even if he were better than Maj, it wouldn't mean anything for the Maj/Supes comparison. Check it out for yourself.
Also adding this because someone made comments about Majestic being depowered and being punched out by Superman:
Majestic was never depowered. There was no crisis that reset his abilities. His powers were never brought low. He's had feats of FTL travel speed and reaction times since WS came under DC, he's moved the Earth and made statements confirming that he can crush it with his hands since WS came under DC, he's survived the destruction of the planet at ground zero since WS came under DC, and beat Eradicator in Fortress mode (a mode in which Superman, even with the Eradicator himself as backup could not defeat) after WS came under DC. There's nothing actually shown anywhere to say that Majestic's power was lowered. As for his fight with Atom, aside from what I've already said about Eradicator, Majestic later showed himself to be his superior physically, even stopping his rage-fueled haymaker with one hand and no effort and tossed him around like nothing. Getting downed in one fight (especially the first fight when neither combatant is fully aware of what they're facing) isn't everything. Majestic has not fought current Supes. He got punched back by Blue Superman (who was able to move the moon, or was it the planet? either way it's a feat Superman can't accomplish on his own now) and he got knocked out by Superman when Hal Jordan was holding him down. Even that though is not really meaningful because it wasn't really Superman. It was a construct of Superman made up by a reality warper for the purpose of defeating the Wildstorm heroes. He was basically a fanboy's dream Superman. (The Fanboy's Dream Batman was capable of successfully using knockout gas on a robot and nearly stalemating Zealot, the superhuman with more combat experience than the entirety of human culture.) I rather attribute it to the fact that he was basically a construct, but it could just be bad writing. I mean, in that story, Jenny Quantum needed a space suit and someone to carry her in order to travel through space.