They're a bit pricy but I've gotten the chance to see the pre-housing crisis models (the company/management group was insolvent for a time) were very solid. The Wacom digitizer is really good for artists too. if they came out with an Air version I think they'd have a rather hot product..
Thus I really like the ideas behind Surface, though Windows isn't ideal for working with unix, which I need for my job.
(I love my Cintiq, but I'd love it more on a retina MBP screen.)