Although I have not stayed at the Clearwater Beach Marriott Suites on Sand Key, I did eat lunch there and checked it out. If I had chosen this property for a family vacation, I would have been very disappointed - essentially no beach!
I know that the hotel I am about to mention is a few hours further south, but my wife and I very much enjoyed the Marriott on Marco Island. In addition, I understand that the hotel has gone through a major renovation since I was there. Or better yet, check out the Ritz Carlton in Naples. Although you can't earn Marriott points with a stay, you can redeem your Marriott Points there!