Very much enjoyed our stay at JW Marriott in Miami. Easy walking to good food, comfortable room. We had a king city view with a rollaway. Rollaway was a little short and daughter on the rollaway was cold. Bathroom was spacious, though shower door leaked a little. Pool was great, clean, warm (for these northern New Englanders.)
We got a competitive rate for this property; however, I snagged it when I saw it and never saw it again.
The only downside was breakfast. Fifty bucks for the three of us and it was not anywhere near worth the money. Go out for breakfast and make it worth your while.
Otherwise, all hotel staff we encountered were excellent, the location was great, and it was a fabulous pre-cruise night for the price we paid.