The graphic tablet I have is the Wacom Graphire 4, it's the 4X5 model, which I prefer because you have a smaller surface to navigate your entire screen.
It uses USB for interfacing/power and the drivers have not caused any issues with anything I normally use. It comes with software that allows you to configure the two buttons that are on the pen, as well as the two buttons & scroll wheel that are on the tablet itself, for anything you can possibly want, from launching programs, to modifiers (Ctrl, Alt, Shift on Windows for example) or custom commands.
The buttons on the pen (depending on how you hold the pen and rotate the pen to access the buttons) can be "clicked" with your thumb or index finger, I really like using this with the UAD Cambridge EQ, since holding down the Ctrl button and "mousing" over an EQ point affects the Q width, so all I do is press and hold the first button on the pen, which I've assigned the "Ctrl" modifier and literally "draw" my settings on my plugins.
I don't know the exact resolution of the pen, but it feels a lot more fine than my wireless mouse (as it should, since it's designed for pressure-sensitive and fine drawing applications like PhotoShop).
The tablet itself has two buttons that are programmable as well, and also a scroll wheel. I really like this because being right-handed, I'm using the pen tool with my right hand, but for example, if I want to scroll down on the edit window in Pro Tools, instead of doing that on the MCU, I just use my left hand and scroll down on the tablet itself. I've set up the far right button on the tablet to do the Bounce To Disk command, and the left to perform the Create New Track command since I add channel/effects busses as needed, so my workflow is super comfortable.
My avatar is a pic of my setup, that shows the MCU & Extender, and my 4 year-old son working the 15k - 20k range, lol. You can't see the tablet on this, but right under the desk is where the pull out tray is and that's where I place the tablet.