most of them actually work great. i have many co-workers that went to other countries and get them (they were on vacation, not there just to get phones. as far as i know and have experienced, most nokia smart phones work well on the voice side of t-mobile, data can be difficult sometimes, depending which model you have (try to stick with nokias that are already out in like t-mobile UK or Germany). go through nokia and they will acually send you an OTA for data access and t-zones, most of the time its free too. langauge packages availible to if you get the phone off ebay.

you would need the $29.99 total internet plan if you have and existing account.