Of your list, I have personal experience only from the Sheraton Bal Harbour, where my family and I vacationed for 3days/2nights late July 2002.

We had a superb visit here and I will address each point of yours:

Dining

My wife is most interested in:
- Great Food <-- can't comment that much about the on-property upscale restaurant(s), as with our kids and friends who had kids, we didn't plan on sit-down meals at upscale $15+ meals per person that much. In the AM, twice, we did enjoy the excellent BREAKFAST BUFFET w/ super views of the ocean. Not "expansive", per se, because I've seen far larger spreads, but the quality was tops as was service. And I won't fail to mention as far as breakfast buffets go, I've seen only one better (St. Regis, Aspen) in years of travel. We also ate once at an excellent Italian place across the street at the mall (simply walked across the street), and not sure what we did a second night. Otherwise, we ate lunches by the pool (hamburgers). On departure day, we walked down the street about 3 blocks and enjoyed a gourmet hamburger at a famous local place (name escapes me, but it was like an Irish pub so the concierge could direct you).

Service

- Great Service <-- Was extremely impressed in all aspects, starting from the greeting by the doormen and ending w/ the personal interaction by JimattheBeach, who actually works at this facility and frequents this thread. If you contact JimattheBeach in advance, you will be treated like a king, and I am sure he would make your wife and yourself most welcome.

- Relaxing Atmoshpere; Physical Beauty <-- The grounds are well-maintained, and plush w/ flowers and gardens. They have two well-maintained hot tubs integrated into the landscape. Additionally, the pool area is quite large, and more a COMPLEX than a simple hotel pool, and I recall you can find several get-away spots away from the pool itself to relax and lounge..or head to the beach about 150-200 yrds from the back entrance. The atmosphere here is really that nice IMO.

- Spa facilities <-- did not try this, so can't comment; stuck my head in the spa and it looked like a typical spa.

Room

- Comfortable Rooms <-- we had a spendid corner suite; as PLAT I/we were upgraded at check-in, though I suspect getting a high-floor CORNER suite might have been pre-arranged by Jim.Can't stress enough if you choose this facility, be sure and make advance contact with Jim and your trip will be enhanced without question. My personal recommendation - try for a ocean-front corner suite 7floors or higher. WOW - the views.

Location

- Not having to use a car (much) <-- We valet-parked ours, and didn't touch it for three days. Key to this was having a facility like this with enough options, both on property and within walking distance, to keep two families with a total of five kids occupied. This place does that ! We felt no desire at all to go wonder about in a car, partly because this area of Miami is very busy and traffic is horrendous day and night...but also because directly across the street is a very upscale mall. No, we were not especially the type to spend money at Saks and such, but made for fantastic shopping and browsing.

Overall

Best of luck in choosing.

P.S. FWIW, the ocean beach at this hotel is expansive, and clean. One of the detractions of the Diplomat, from numerous postings, was the smallish beachfront. Also, if you wanted to wonder back to south Miami/South Beach one day, its straight south maybe 10-15 mi on the very road in front of this property. Simple to get to.

PSS. High-speed DSL access works great here if you have need to get online.