I don't like it. For one it has no pressure sensitivity even after downloading the addon that's supposed to make it work with tablets. For another I find most of those brushes to be completely useless. They're cool and all and fun for messing around but I'd find more use from a square or angled brush. It also ate up most of our bandwidth and that's just not cool.
In short, I could make the exact same art with the updated Paint that comes on Windows 7 and not cause our internet to crap out. Though I suppose it's great for people who don't have something better.