I stayed in December. It was the least-bad Marriott option in PR so far (otherwise, the AC and Courtyard Miramar are nice). Haven't tried the St. Regis or Ritz or Four Points Caguas yet, Also will eventually try the W Vieques and the various other Courtyards.

Absolutely avoid: Marriott itself (horrible on every possible axis). Not a big fan of the Sheraton OSJ (although it's in OSJ), and meh on the Sheraton Convention Center (nice lounge, otherwise meh).

Upsides of La Concha are location, lots of on-island big parties there, great restaurant, beautiful common areas. I got upgraded to a suite in the tower, was large and comfortable but definitely not luxurious, but perfectly nice, and a great beach view. La Concha or the Condado Vanderbilt are pretty much where I'd recommend out of town visitors to stay (I live here now...)