I would say it's pretty good if you're really tied into Windows, and even better if you're a Windows developer.<p>If not, I'd go with a Nokia N900, Blackberry, iPhone, then Android, in that order; the N900 just has a ridiculous number of features, Blackberry has built their business on enterprise support, the iPhone has good hardware and is relatively easy to develop for (if you want to), and Android is just a bit "meh" for me at this point.