We stayed at the Fiesta Americana Grand for our Honeymoon, and although our travel agent had explicitly marked this on all our accomodation, Fiesta Americana didn't acknowledge this which was disappointing.
However overall it was an excellent stay. We had two rooms, firstly a club access room with a wonderful view over the resort and the ocean (with Whales going past, no less) and secondly we got upgraded to a Grand Master suite when our room was needed for a tour group in the middle of our stay. Both rooms were clean, well maintained, large and comfortable but the Grand Master suite was well beyond that, being twice the size of a regular room with two bathrooms and a separate lounge.
The pool setup was great (one of the best we've seen) and the private beach area was clean with comfortable lounges and shaded areas. However the beach area is not one for swimming due to the large amount of rocks there. There are small areas where you can swim however it's not a place for people who want to do a lot of ocean swimming right from the resort door.
Food overall was very good, ranging from excellent Italian food in the dedicated Italian restaurant, very good pool service and lunch food to dinners that are a little hit and miss (although nothing short of good quality).
The only consideration is that if you want to spend less time lounging at a resort and more time exploring Cabo itself, the resort is along the resort corridor between Cabo San Lucas and San Jose Del Cabo, and thus it's a bit of a trip into either. Taxis are $20US no matter what, but the resort provides a shuttle bus with set departure times. Be warned though that if you want a night out in Cabo that the shuttle bus has a reasonably early last departure from town (I believe it was 9pm).
If you want to spend most of your time exploring Cabo, you may be better off looking at a hotel or apartment in town itself. However if you want the resort experience then I can highly recommend Fiesta Americana.