The screen is HUGE, to the point that it almost becomes a tablet - yet it is still a phone. The screen makes the phone a little big, but given that the screen goes practically up to the edge of the phone on all sides, it's efficiently proportioned. And I find I can get v productive on it - writing longer emails, reading ebooks, etc.
I get all the benefit of Android (see elsewhere in this thread), Sprint (which is actually v good coverage in SF and other metros), 4G coming soon and unlimited plans for $59. Wifi tethering is free if you r00t the phone.
You won't have any problems with running linux with it (for a start you don't really have to connect it to a computer for anything unlike the iPhone) whereas it's practically impossible to run iPhone + linux effectively (via Wine basically, urghh)