I've spent a week at Grand Velas in Vallarta about 3 years ago. As far as AIs go, I thought it was great and it did exceede my (low) expectations. Even though they boast being 5* and a LHW, I'd give it a solid four.

Pros-
Good staff.
comfortable lounge chairs at the pool
Piaf resturant was very good

Cons-
Reservation process for sit down restaurants was inconvenient.
Room furnishings were rather sparse and cheap.
buffets and other restaurants were average at best