When the Green Lantern Corps was first conceived, the Power Rings were supposed to be these highly advanced technological constructs that the Guardians built using their extensive scientific knowledge. Sinestro's Yellow Power Ring was also a highly advanced piece of technology, but it was built by the Weaponers of Qward, a technologically advanced species from the anti-matter universe.
However, with the introduction of the emotional spectrum, it seems like the other Corps are able to easily make power rings that are as powerful as the Green Lantern rings.
Wouldn't it make sense to if the powers of the different Corps depended not just on the emotion they used but also on their tech level? The Green Power Ring should be of the most advanced design and construction since the Guardians possess the most advanced science and technology in the universe. The Star Sapphire Ring would probably be the second most advanced since the Zamarons are close to the Guardians in terms of tech level. Yellow Power Ring would probably be third as their creator, the Weaponers of Qward, are one of the most advanced races in the anti-matter universe. Blue Power Ring would be fourth, being made by Ganthet and Sayd. The Red and Orange Rings would be the least advanced because the Orange Ring is ancient and Atrocitus isn't a scientist. Not enough is known about the Indigo Ring to make a judgment.