I had been to the Marquis in Dubai and it is truly spectacular. I couldn't really imagine the Miami JW Marquis could match it? Happily I felt the same level of exquisiteness, professionalism and excitement. It's an amazing hotel and if you can pull off an upgrade its top notch! The location is great! Only walking distance or short ride to and from all the Miami essentials (as long as there is no traffic :) )
I cannot recommend staying anywhere more awesome than a JW Marriott Marquis! It is so lovely!