Your first reason is why I like Resident Evil Zero so much. I don't mind backtracking thus the item dropping mechanic was not a big deal. I liked being able to explore the train, training facility, etc.
As for being linear, based on the playthroughs I watched, yeah the game seemed to have a big problem there. That and the fact that the gameplay mechanics seemed all over the place.
The overall story of RE6 I thought was ridiculous (A man in love in Ada is what caused all of this?) but I thought the way some of the characters were presented was great. Chris finally wasn't stiff for once, Helena was a good character IMO, Sherry's return was treated ok (could have been better, but could have been worse too), and Jake's character development, no matter how typical it was, was nice to see in a series not exactly known for its character development. I personally thought Piers was average, and Leon and Ada were just stiff and boring in this game.
