I enjoyed the demo myself. I have a few problems, and I'm sure I wouldn't like it as much had I not played it with a friend doing co-op. I'm with you Yggdrasil, in that Jake and Sherry's was probably the best one, and Chris and Piers was my least favorite. I think I would have enjoyed C&P more had I had a better grasp of the controls, since there isn't really time to get acclimated, considering you have to find cover almost immediately. The whole cover aspect kept screwing me up, because the last game I played with cover mechanics was Mass Effect 3, and I kept trying to emulate those controls, and ended up leaping over my cover.
I really wish they kept Sheva as Chris's partner. That whole co-op partner dynamic was the point of the last RE. The only reason I can see them replacing her is to try to make Chris's story into a Hollywood war movie, and thus that means a band of male soldiers.
Best part of the whole demo? There were two for me. The first was in Leon & Helena's campaign, where they have to get out via cop car. What a huge nod to RE2 that was, I was grinning the whole time. The second was realizing that the voice actors for Jake and Sherry are the same for Yuri and Estelle from Tales of Vesperia, which gave me a bit of a fanboy moment.