I think I'm in either chapter 2-2 or 2-3 (playing on Normal), and I'd say it's decent so far. I've adjusted to the controls, and at this point my biggest gripe is with the autosave system. I'd really like to be able to version my save files like in RE4, and the the inability to do that is kind of irritating. Also, I think it's interesting that the game allows you access to the item shop every time you game over or reload, so I exploit this wherever possible if I need to sell some stuff to free up space or need to upgrade.
As for Sheva, I've gotten pretty good at keeping her away from my handgun ammo, and I'm seriously thinking about simply selling her M92 so she CAN'T waste it, but I never have quite enough machine gun ammo (I've trained her to use the MP5 as her primary gun) to be willing to go that far (at least not yet). I wish she'd wait a little longer before blasting the green herbs, but I have noticed that she will use the weaker herb if your health isn't so far down before she wastes the stronger herb.
Outside of that, I'm really happy with the graphics. The effects seem beefed up over the demo, and the level of detail is really impressive. I kind of wish they didn't reuse so many of the design elements from RE4, as there are parts where it looks like RE4HD instead of a new game. After my first QTE encounter, I was pleased to see that these have been made more forgiving than in RE4, so pressing X to Not Die isn't as much of a pain as it was in RE4.
The linearity of the game (at least so far) is kind of a drag, but perhaps things will open up a bit later on. I think at this point it's pretty clear that RE5 is not earth shattering like RE4 (one of the best games I've ever played), but it's still pretty good, and here's hoping it gets better as it goes along.