I've actually read quite a few positive reviews, much more so than negative ones.
I enjoy it quite a bit. Yes, there's a learning curve, but once you get past the fact that it's different, you'll see that the changes actually make sense for the most part. The switching between Metro/Start and Desktop can be a bit jarring initially, but it's really not that bad. It should work really well on a tablet.
I should admit that I have a Windows Phone and Xbox 360, so this Metro styling is quite familiar to me already. Regardless, once you get over the fact that it's different, you can begin to appreciate the innovations.