No experience with that specific resort; but, I have stayed in a few of the Riu's around Puerto Vallarta and was always satisfied with the service, etc.
The Playacar area where the Palace Riviera Maya is gated, quiet and safe. I have spent some time in the area; and, there are many on this board who have spent much more time around here.
If you do stay in this resort and want to get away from the crowds a bit, walk south down the beach past two or three other resorts and enjoy a completely deserted area of beach.
If there's one thing in my life that's missing; It's the time I spend alone
Sailing on the cool and bright clear waters; There's lots of those friendly people
Showin me ways to go; And I never want to lose your inspiration