As a whole I think the corruption gear is really bad for the game. It's a horrible system. But the idea of changing gear based on content is fine.
Pros:
I like the overall idea of changing gear based on the content you're doing. Using the same gear for all situations is not really fun. Historically trinkets have been the gear you changed based on different scenarios but this can beneficially also apply to other gear.
With the corruption system, it is however only applicable to some specs right now. For a BM hunter for example the best corruption is just pure stat increase in (almost) all situations. This kinda neglects the purpose. But the idea is fine.
Cons:
RANDOMNESS. Both in acquisition and in combat. This just doesn't feel good. It's not fun or satisfying. The acquisition method of corruption gear is completely horrible. Hopefully Blizzard knows this and will make it better in Shadowlands based the weekly chest with multiple choices etc. Even worse is the complete randomness in combat. You have no control of your dps and things like Twilight Devastation can even randomly pull mobs in dungeons. For example on Vol'kaal ("second" boss in Atal'Dazar) where TD can pull the mobs outside the boss arena even when the gate is closed. Randomness like this is not satisfying in any level.
TL;DR: The idea of changing gear based on content is fine but the specific execution of the corruption gear is horrible mainly based on all the heavy RNG in both acquisition and combat.