Yes, I've used European Transmissions. I have a 722.605 (early electronic) which I removed and took to them to rebuild 6 months ago. They do the rebuild themselves, it took a few days. I decided I'd rather have them put it in, which they did. They have a Star diag system, they also updated the software on the transmission computer (ETC). No problems, they did a good job at a very reasonable price.

In my research, TBR seemed less flexible, i.e. I was told that if I had a valve body rebuild, they would not credit that toward a full rebuild. I ended up doing the full rebuild anyway, so it didn't matter in my case.

If you plan on removing the transmission yourself, I'd advise reconsidering. The factory manual isn't great. I should have made some notes and posted them. One thing I do remember: I had a hard time getting it out after it's disconnected and unbolted. If I remember correctly, you have to pry the torque converter away from the drive shaft with the transmission in place. If you don't, the transmission will just hang on the torque converter. They included a new torque converter as part of the rebuild, so don't worry about damaging it.

David