Sounds like a lot of different experiences, maybe it depends on the time you go. I was just not impressed with the Mexican bar, not just because that is my heritage, but because an $8 taco salad should not consist of two hard flat tostada shells with a few ingredients on top. I had a GREAT taco salad at the All-Start for the same price. Now, I didn't get to try a lot of things, because my wife wouldn't go back, but $4.50 for a hotdog and small bag of chips did seem high even by Disney standards.
Now, I will say that the staff was friendly and professional, even though we did have to wait till the end of lunch to get anoffer to refill our teas.
Maya Grill may indeed be a fine restraunt, we passed it up to eat at the San Angel. Now, that was one of the finest meals I've ever had.