Today, I tried out a Cintiq 21UX at my university (which quite ironically do not let students use). And I was amazed beyond amazed. This stuff costs almost £2000 if you can get it somewhere else, it can even be £1500 but still... Jesus. I felt skeptic towards the Cintiq, now I see why it's such a big deal.
When I came back home, I went straight onto my Intuos4 tablet (medium size), to try to quickly compare. And obviously it completely dominated it. However I have not too much trouble with my current tablet, I notice whatever I draw on the Cintiq is quicker, and comes out correctly. Unlike trying to draw without seeing, or when your monitor is a different widthXheight ratio as your tablet. I realise.... Cintiq is totally the way to go.
12WX is a smaller and cheaper Cintiq, and I was considering saving for that but the 21UX was so bloody impressive, I don't know what to think.