Off My Mind: How Powerful Are Darkseid's Omega Beams?

Darkseid is one of the most ruthless and powerful villains in the DC Universe. His prime weapon would be his Omega Beams. They have been said to be impossible to avoid and capable of vaporizing, erasing, or transmuting any form of matter, living or nonliving. That sounds impressive to me. 
 
The question on my mind is, how powerful are those beams? What exactly are they capable of? Over the years, we've seen different effects from getting hit by the beams. It has been said that Darkseid can even resurrect someone hit by the beams. In some ways, this truly gives him godly powers. Basically this is Darkseid's absolute way of giving someone a time-out for however long a period he chooses.
 == TEASER ==
In Martian Manhunter #34, we saw that the beams can also transport himself or others through time and space. If this is the case, couldn't Darkseid travel to the future to see whether or not he will be able to defeat Superman or Orion? Depending on how messing with the time stream works (that's a completely different topic), Darkseid could also go back in time and change things so he isn't so easily defeated by his enemies. 
 

There's also the question of how come some individuals seem to be immune to his the Omega Effect? If he can vaporize any form of matter, how come he hasn't been able to vaporize Superman? Is Darkseid himself immune from his own blasts? In an animated episode, Darkseid is about to blast Superman, who quickly clamps his hands over his eyes. The blast knocks Darkseid back and injures him. 
 
Where do his blasts stand in terms of strength? Is Superman's invulnerability stronger? What about Wonder Woman's bracelets? Could a Green Lantern block the beams?
 
 Even without his beams, Darkseid has demonstrated acts of super strength, stamina and speed. As evil and dark as Darkseid is, he simply deserves more respect. With his beams and an entire planet under his control, he shouldn't be so easily defeated. Darkseid may be "dead" at the moment, but it's only a matter of time until he returns yet again.