I just left 3 after only 2 months, because off poor call quality and dropped calls. I had the following conversation with the guy giving me my PAC code:
"What handset do you have?"
"Nexus One"
"Is it a 3 handset?"
"No, I didn't get it from you"
"Ah, well that will explain the dropped calls as not all phones are compatible with our network"
"No, you have a GSM network and I have a GSM phone"
"Yes, but the 3G network is only a small part of the specification"
"3G is part of the GSM standard, I have a GSM phone"
Idiot