I've used a ton of tablets and although I'm not really qualified to give a review of them all, I have to say the graphire4 is very suitable for just about anything you could put it through, probably my favorite non-lcd tablet since the original Intuos :p
Personally I coughed up the extra money for an LCD tablet (well not really, I got a pretty good deal on it :p) and love the heck out of it. As far as pixels go, I use it a lot more for figures and lines than I do for tiles, textures, or details, but during the course of a piece I tend to flip between mouse and tablet a few times regardless of what I'm working on... being able to draw directly on the screen is simply too badass to pass up. Plus, extra monitor.
From what I've seen a lot of people don't like lcd tablets, or don't think the extra expense is worth the benefit, but if you can afford it it might be worth a look.
The best advice I can give to someone looking at buying a new tablet is to try some out in a few different sizes to see which size suits you the best. Most people I know prefer a smaller size because they can make big sweeping curves with minimal movements, but it all depends on how you work. Mine's a 17" monitor (13.6x10.2 inches, if my math is correct) and sometimes I wish it was a little smaller, but being able to draw on the screen as well as have a full-size secondary monitor more than makes up for that. The tablets at my school are gigantic, and quite unwieldy imo, especially when you're used to high mouse sensitivity.