There are a couple of sources online I've found to be reliable in terms of judging properties.

1. This Forum. (On its homepage, http://www.flyertalk.com/forum/forumdisplay.php?f=427)

using the Search Mechanism and you'll see the views on Marriott properties by a group, the members of which, frequent them with extraordinary frequency for business and pleasure. Often you'll see some very dtailed trip reports that delve into minutia and subject matter that you won't see anywhere else.

2. A second is www.tripadvisor.com where you'll see objective ratings and subjective opinions including those of participants in Marriott Rewards and also the more casual pleasure-only traveler.

I've found that researching on both sites when I'm personally unfamiliar with a property and am contemplating a pleasure stay that's going to cost a not inconsiderable amount in currency or points gives you a pretty good idea as to what to expect.