I found that with the combat in 3, but you soon get used to it and I thought it was actually an improvement, moving you away from constant block-counter-block-counter fighting. The rifles are annoying, but again you soon learn when they are going to do it and even if you haven't got anyone near, just run like fuck sideways (as they stay pretty straight on when they are set up) and you can avoid most of the shots.
The boat is really boring, but the rest of it is alright. Apart from the village folk scanning bullshit (don't even bother with it, waste of time).
I actually liked AC3 (I think I might be the only person here who did). Connor isn't an interesting character at all, and the bow and arrow is such a waste of an idea (see Tomb Raider for how to do it properly) and the complete lack of proper buildings/cities does hamper the game A LOT, but the combat is much better and I actually enjoyed the naval missions and the bits around that. I haven't played 4 yet (waiting till I get a PS4 probably around Christmas) but I'm hoping they've kept the new combat but gone back to having proper cities to run around (there must be naval stuff given that he's a pirate?).