Leon's campaign was my least favorite by far. It was so slow paced and boring, with absolutely no TRUE exploration or puzzles anywhere. It was so utterly dry and boring, and he barely has any good weapons for something that, when you strip away those stupid "points" that replaced all the cool gems/items/customization etc from RE4-RE5, RE6 is truly nothing but an action game, and Leon's campaign tried so hard to be more when... it had nothing more to offer. Where was Leon's snarky humor too? Hated it.
Also Leon's new partner SUCKED. Sheva was cooler, and Sheva isn't very cool. I can't even remember Leon's partner's name anymore. So forgettable.
From a gameplay perspective Chris and whatever the other guy was (already forgot his name) had better missions and was more fun. Ada's was whatever since it had some copy/paste sections.
RE5 streamlined things big time after RE4, but the gameplay still had way more to it and there's tons of replay value. The point/skill system for RE6 was so lame.
RE6 is hardly as bad as most make it out to be though, but it's not amazing and probably nothing I'll ever replay. 6/10 for me. I like it more than Revelations. My mind explodes when people think that was taking RE back to the roots. Awful combat worse than RE4-RE6, and some of the worst characters in the franchise history. Are you reading this Popo? Steve from CV is far more likeable than half of Revelation's cast. Well basically, every new character was garbage and the fun B-grade cheese and charm was nowhere to be found anymore. Finally... we get Jill and Chris together in the ultimate budget title that's fan fiction come to life! I'd probably give Revelations a phat 3/10 or something.
Still want to give Revelations 2 a shot though.