I have one, its ok but the battery life is not amazing (my Wife’s iPhone 3gs is much better). They have just been updated to Android 2.2 which is supposed to improve battery life but I find I still need to charge it every night.
Having said that for me it is not a problem to charge every night and I do like the fact if my baby gets a hold I know that it will be ok. It can also can be washed off in the sink to keep it clean. I use a case and screen protector with mine as I don’t trust that the screen will not be scratched.
The phone has the swype keyboard which once you are use to it makes a lot of sense for typing. I find the screen easy to read and works well in all light conditions. I also like the way that you can customise the screens and the notification lights.
For me it was the only choice mainly due to it being waterproof.
Hope that helps.
Nick
PS There are a few other threads on this if you search back up to about one year.