The new, smaller Cintiq is a really good idea and I love the format, but they didn't follow through and make it usable. I got one at work and it picks up RF interference like crazy. Worse than my old Graphire tablet, and that thing would get interference from radio signals and cell phones. So after a couple weeks working with the IT guys and separating out all my cords and trying different locations, we ended up calling Wacom, and they basically told us that the 12wx isn't shielded as well at the other Cintiqs and is not intended for serious workstation use. It's not just one faulty monitor, it's the whole model. The IT guys are attempting to rig it with some kind of aftermarket shielding, but it's probably not going to work and we'll have to return it for one of the bigger ones.
If anyone out there is considering this great-looking, smaller, cheaper, more portable tablet monitor... Keep saving up and get a big Cintiq instead.
I also have a Modbook - and aside from some huge problems with OSX which I think are my fault, the feel of that thing is great. It's got 512 levels of pressure sensitivity, and the surface of the glass actually felt nicer than that of the Cintiq... And no interference at all... And it's a self-contained computer, which gives it points over the Cintiq, and has all the usual Macbook ports *and* an optical drive, the only slate tablet that has that. People have asked me about lag, and honestly it seems like the only times I've noticed any lag at all were in the write-anywhere handwriting recognition (just a pause between starting to write and having the little balloon for your writing pop up) and a little in Photoshop - and they seemed to be software issues. The lag when drawing a line in Photoshop was the same as doing so on an Intuos.
There was a bit of getting-used-to with it, especially being a PC person, and at first I found the thing totally frustrating (mostly the lack of a keyboard, but it's got USB ports for that). But as far as a direct digital drawing surface (tried the Fujitsu Stylistic a bit too) I haven't found anything that really matches it. Plus it's not Vista... I really wanted a tablet laptop but not Vista so it's really the only option now that Vista's on all new Windows laptops.
So anyone out there looking for a direct drawing surface... Just some personal experiences to help you make your choice.