I mostly love the phone. My biggest complaint is that the indicators for voicemail, missed calls, and text messages are small and non-obvious. Also, you can't change the ringer volume (such as to set the phone to vibrate) without going through the process of turning on and unlocking the phone-- I'm used to just flipping a switch on the Treo. The email app is pretty crappy.
Google turn-by-turn driving directions are good if a bit rough-- I've gotten some of the voice commands a bit later than is reasonable. The screen is fantastic, and the keyboard is starting to suck less. Voice search is an amusing toy, though I couldn't get it to search for my name-- it insisted on searching for Patty Beatle.
Still, it's a pretty slick phone, and way more usable than the iPhones I've played with.