I am thinking about getting a graphics tablet. I am trying to learn Adobe software and I thought it might help to get a tablet since most things I draw with a mouse look like poop. I've started looking around and I'm not sure what I want. How big a difference is there between the sensitivity levels?(I'm can't afford the higher ones unless I get lucky on ebay) I have a Dell with XP and I'm not sure what would work best. I'd like to be able to draw as well on the computer as I can with pen and paper. 