I'm in the process of playing Chris's campaign, which I have a feeling is the only one I'll like.
It's my first run-through and I'm playing it on veteran. Ammo gets tight on Veteran, so I resort to using the knife to conserve on ammo. Using the knife to defeat enemies is so much easier since you can move and use it (you can also shoot and walk). I like the challenge.
First off, the enemies could have been more creative. Some are some stupid half-grasshopper hybrid and some others are some stupid half-spider hybrid. It's actually incredibly cheesy and unimaginative.
Chris is perpetually angry and Piers sort of butts heads with him, but ... I didn't mind them so much. Chris was reckless at points, and Piers is sort of like a protective younger brother. I felt they had good chemistry in regards to their relationship.
The action is actually not that bad. It takes a moment to get used to it. I think initially the camera angle is a bit too fast, but altering it in the options fixes it.
The story ... where do I begin? It's lame. It's cheesy. It's ... again I use the word, unimaginative.
Another thing? I dislike Ada. Her wannabe Batman bullshit is obnoxious. She virtually has no flaws marysue. They focus too much on her. They focus too much on her 'relationship' with Leon.
Leon's story is ... boring. It's like they tried too hard to get back to the roots, they touched upon it, and instead of mixing it up a bit to keep it fresh, they kept it stale. Stagnant, even. Helena is whiny and nosy, constantly questioning his 'relationship' with Ada.
They also altered the RE universe to fit this storyline full of more plot holes than a slice of Swiss cheese. Chris has no idea who Ada Wong is. Um, how is that even possible? Previously, we were told he, Claire, Leon and Jill were part of an anti-Umbrella movement, and suddenly they're in separate organizations with little to no contact. Which is it?
I haven't done Sherry and Jake's story yet, so I can't comment on it.
The game could have been better in regards to the story. When the stories intersect, it's forced, it doesn't flow naturally. The enemies become stale after a while. The Quick Time Events (QTE) are obnoxious, because the game is peppered with them. Sometimes I just want to watch a damn cutscene.
Honestly, Chris is my favorite character and Piers has become a close second. I will replay the game to get the most out of it, but I think I'll enjoy Chris's segment the most. I could look past the enemies being boring if the story were more enthralling, but it's a letdown.