i saw a thread like this on cgtalk. Alot of people have said that the
wacom intuos3 6x8 was the best choice for a tablet. It has 1024 layers of pressure, where the graphire only has 512. Also, the intuos has the pen tilt feature which definately puts it way above a graphire.
Think of a tablet as an investment, because alot of people swear by it. I myself want to get one too, but i need to get some money first.
And, alot of people say 6" by 8" is the way to go, anything bigger and its not really worth it. The intuos3 6x8 is like 250 or something. you'd have to look.
www.wacom.com