Received a unit yesterday, I had ordered via eBay. Works perfectly on both 3G and HSDPA. No problems with either voice or data.
Since I haven't been able to activate the phone via Sprint:
1. It tries to connect to Sprint each time I boot it. I need to then make changes to network settings so that it can log on to the local GSM networks.
2. Each time I send a text message, it reminds me I might incur international roaming charges.
Rest is super.
(1) Google Nexus S
(2) Motorola Photon 4G