I've been playing with it instore and I just don't like the UI. It still feels sluggish and as snappy compared to the iPad 3. I found the same experience with the Galaxy Tab 7.7 and Galaxy Note handset also. The S3 on the other hand is perfect.
Which shops have them in so far?
I'm very tempted by one of these to replace my Touchpad. The pen looks like it could make the device great for taking notes at uni. I could have all the lecture notes (powerpoints/pdfs) saved on there, and annotate them on the go. Same with the textbooks I've got (all PDFs). Could be quite a useful feature, in addition to all the usual tablet features.