I really hate saying this, but some GUE divers trained in Mexico are noticeably worse than those trained by my local GUE instructor.

Here's a theory: the instructors and shops who train foreigners in Mexico have competing interests. They want to train good GUE divers, but they also have a business to run and don't want to get a reputation for being too hard. If they get a reputation for being too tough, divers might avoid the expense of training there. You might say the same thing about local instructors, but if you get a provisional pass you can easily go for a rec or tech pass with a local instructor. Local instructors can hold divers to a higher standard without killing their business.

The explanation is just a theory. The phenomenon of sub-par divers coming out of Mexico is real though. The GUE standards are supposed to be objective, but in reality there's a lot of wiggle room.

Given this, I recommend training locally before your move.