I have a Wacom Cintiq Companion 2, the one with the Windows operating system and i7 processor, it's like a little turbocharged tablet that has everything I could ever want. It brought my game up to a whole new level. The disconnect between the traditional drawing tablet and the monitor is pretty big, and to me, really limited what I could do in terms of intricate brush work, and now I don't have that problem! It runs Illustrator and Lightroom and Photoshop at the same time! I can take it anywhere, it does not need to be attached to my main computer, so I can draw in bed or out on the hiking trail (electronic plein aire, and it has a camera, you can take the scene with you!).
They are absolutely amazing, I cannot recommend it highly enough.
Stacey