First impressions, it's a nice compact and solid unit. Significantly smaller compared with the 680 and also significantly lighter.
I had problem putting in the Sim card until I was told one had to remove the stylus first, duhhhh. But I did not have the benefit of a manual.
The battery is a different model from the 650/680's in the sense that the contacts are positioned differently. It looks like a 1150 mAh battery in the evaluation unit. I have not had it long enough to test out the battery life yet but will stress it out with always on IM etc. and see. However the connectors and battery charger slots are the same. So you could charge it with the 680's charger.
The screen and the keyboard are noticeably smaller than the 680's but the screen is very sharp since it is 320x320 resolution and easy to read.
I find the keyboard tiny and there is no space between the keys unlike the 680. I could still type fairly easily on it though, The layout is the same as the 680 except for the hard buttons. Anyway you would have seen pix of the Centro in the earlier posts in MPC or elsewhere on the net since the US CDMA model by Sprint is already out.
The Centro is very snappy. The 680 in contrast was slightly laggy (compared with the 650) but somehow the lag is absent in the Centro. This is one very nippy Palm.
More later....