The action and setup is different, becuase they are designed for diffrent markets. The mex and Japan strat are easier and faster to play, but lacks the control an experianced player needs.
Just go play them and get the one that feels the best.
If you like the American strat get a used one. Most of the time they are better. New ones can change over time and you could get a lemon.
You will be happy with either.