As I alluded in another topic, I picked up this game this morning and have made some pretty good progress (I just had my first run-in with William Birkin). So far, I can say this game is easily a dramatic improvement over the last Wii lightgun game I played (Dead Space Extraction) and a definite step up from Umbrella Chronicles, partly due to simply being set in RE games I actually like and partly due to the greater immersion. Going into this game, I really didn't think I'd like the "Shaky Cam" ruining my shots, and to some extent that does happen in places I'd rather not (usually when I'm trying to grab elusive items) but overall I think I'll take the trade-off for the greater level of immersion. Overall, though, it's not as bad as reported (in the spots it's worst in, you generally shouldn't be shooting anyway) and my aim's been fairly decent with my Wiimote in its Perfect Shot holster. Getting head shots is still harder than I would like (frankly, I think it reasonable to consider it a "head shot" when you blast a zombie in the face, but that's just me), but it's a lot easier than it was in Umbrella Chronicles.
Overall, there are just a lot of little tweaks here and there that make for a better experience, such as having the gun selection mapped to the control stick; being able to store and manually use green herbs when you need them; a little more lenient timing on the QTEs; automatically acquiring gold you find shooting objects without having to "grab" them; and having the second player often on-screen with you (with their own health bar, even).
So far, I only have two real complaints and a nitpick: first, it's a lot harder to tell what you can and can't break in this game. In Umbrella Chronicles, your crosshair would change to indicate when you can break an object, but here it remains the same on any piece of the environment to make it a lot harder to find hidden items. Second, I'm not sure why but there's just something about this game that doesn't look right, like there's no anti-aliasing on anything and the brightness seems off (ironically, the exact opposite of Extraction's problem: here, the game seems too bright so textures seem washed-out) with no way to fix it in-game (I'm not messing with my TV's brightness for just one game). The end result is that the game looks really rough and kind of ugly on my HD TV, even though I can tell from screenshots that this game ordinarily looks quite decent. It's not a Wii thing, since I've seen plenty of Wii games that looked just fine on the thing, but for some reason 3rd party Wii games always look like this.
Finally, the nitpick: ok, Capcom, you stated quite clearly that you were going for better immersion in this game and I definitely believe you succeeded in your goal. That said, if you wanted to give a better sense that I'm "there", why is it whenever my character does something I never see their body? When my character slides along the ground, it's just a camera sliding. When my character pushes open a door, it's a camera pushing the door. I'm sorry, but that's one thing Dead Space Extraction got right, so it's disappointing to see this crop up here when so much else is done right.