My boyfriend and I spent a week at the Miramar Condos, and I can't think of one complaint if I tried. Isabella and Matias, the owners, are extremely helpful if you need anything at all. The place was clean, private and exactly how the pictures portray it on their website. Just a general suggestion for Cozumel travelers - definitely rent a car. There's so much to see, and cabs can get pricey and limit you. Isabella can set that up for you and have it waiting at the airport. Also, if you set up the Pirate Ship Dinner (lots of fun), make sure to set it up through Matias to make everything much easier.
I highly recommend it here and I can't wait to go back!