I did 6 months at Mountview in London, but found that while I grew as a person from the experience of living in another culture, most of the specific stage management information didn't translate back into US theatre. While I don't regret my experience going, I could have gotten the same experience studying almost any topic. I met folks over there taking other types of courses at different universities, not geared towards their degrees, but just for the experience of being overseas.
Mountview's program for apprenticeships is basically a trade - they let you work on the shows in exchange for you being there with no tuition. But you're on a student visa, must be able support yourself without a job, and be able to prove to immigration that you are able to support yourself without recourse to a local job for the entirety of your stay. At the time I went, to get a local job (with a student visa) the employer would have had to prove that there was no one else who was a citizen who would be able to do the same job.
While I reccoment highly the experience of going overseas, my personal experience says it almost doesn't matter what courses you're taking - its the experience of the culture that's going to be the most benefit.
-Centaura