I have a Blackberry with a US-based T-Mobile SIM card and it works perfectly. I can text without editing international phone numbers, I get all my email, the web browser works just as quickly (i.e., slowly) as it does in New York, and the SSH application I have is also fine. It didn't work last year, but something happened between December and April and now it's fine.

I do not know if it works with a QTel SIM card. I've only seen people with QTel cards in Windows smartphones.