My experience with T-mobile has been great. I pay $.99 per minute for airtime when I'm in Europe, including roaming and long distance (whether I'm calling within Europe or back to N. America).
The first time I went to Europe I had trouble getting the phone to be recognized by the network. I called customer service (using a land-line, obviously) and they quickly walked me through the steps to get it working. My phone just wasn't switching between networks automatically even thought it should have, but now I know how to 'force' this to happen.
I've had great reception, no billing problems, terrific customer service.
On my last trip, I did notice that it could take several hours for me to get notified that I have voicemail, which was irritating. I don't know if this was unique to me or if it is a widespread phenomenon. I should probably look into it, but I've been lazy.
[This message has been edited by CanuckFlyer (edited 04-07-2003).]