For what it's worth, and this is only second hand information but have heard it from a couple of friends now - the training in EMA is better.
The reasons I have heard for this include that CAE AMS uses non FR instructors as well as some FR ones, which causes some standardisation issues, and also that the sims they use for the initial part of the training in EMA are proper FFS sims whereas in AMS they use some sort of fixed based touch screen overhead trainer.
On the flip side, I have heard socially AMS is nicer, but is that what you are there for?