We ate here for lunch this past Tuesday. I had been concerned because the last time I was at SAI (in 2004) I hadn't been impressed, but the atmosphere is AMAZING in the Mexico pavilion and so I knew we had to try again. Well, I'm SO glad we did - the food was delicious. The ribeye tacos are legitimately amazing, as are the crab tostadas and the chicken tostadas. Partner had the enchiladas and ate them so fast I didn't even get to try them!
The only complaint I had was that they didn't have unsweet iced tea - every other table service was able to get that for me, so it just stuck out weirdly. And that's not even much of a complaint. Go for it, you'll love it.