OK, so here's the drawbacks i collected...
- Pretty heavy. Despite the small size it is nearly 2 pound, so more than double the weight than some competitors
- Fat. While i like the small size the height of the unit is too much for my liking. Even more when you use the extended battery.
- The little display. While pretty cool i never managed to display anything else but outlook related stuff. Too bad no SDK...
- The extension port. I think the only extension available was a better camera. The connector is very fragile, too. I broke off mine from the camera by just placing it on a table.