We love Mexican restaurants and we've tried this place twice. Both times, I was very disappointed. Both times, I asked for substitutions and was told no also. The service here was AWFUL both times I've eaten here.
The most recent was May 5. It was my best friend's birthday that day and we chose this place because she asked to eat here (I wasn't thrilled, but it was her day, so her choices). I metioned at the time of the reservation, when we checked in, with our hostess and our waiter that it was her birthday and nothing was done or said. Not even a Happy Birthday from the hostess or waiter.
The service was SO slow. We had a reservation at 7pm (did this so we would not miss Illuminations). We were not seated until almost 8pm and we were not done eating until almost 10pm. YIKES ... 3 hours wasted on so-so food and terrible service!
I do agree though the atmosphere is to die for here. IMHO, that's the only thing going for this restaurant!