Posting this on an n900... Very low battery life, bad touch screen, sluggish ui. Why on earth did they cripple the default shell? The keyboard is pretty nice. When someone is calling you, the answer and decline button jump around in the screen, and I always hit the wrong one. This is because of the orientation sensor and the slow ui rearrange. Most browsing frustrations go away when you start using Opera as the browser. Most of the bugs in the builtin apps could have been fixed relatively easily, but I guess they restarted with a different ui paradigm after N900. Never used android or iphone so don't know how bad they are.

The battery life is certainly an issue, but I find the UI just as fast as the equivalent Android. I also love the touchscreen because of the stylus.

You can prevent the orientation sensor from making things jump by forcing either portrait or landscape mode in the phone-ui application.

Most of those bugs in the apps have been fixed in the Community SSU: http://wiki.maemo.org/Community_SSU

for one, a very, very annoying bug where, when you get a phone call, the phone app can take long enough to swap in that the caller gives up.

Ah, I forgot about that! I originally fixed that by installing a modified hildon desktop, but that's been incorporated in the community SSU: http://wiki.maemo.org/Community_SSU

EDIT: I also had to force the phone-ui to landscape mode so it wouldn't jump around on me.

yeah, been meaning to move to the community ssu when i get a free weekend.