I realize your trip is over, but I'll add my two cents for anyone else looking for info. Of the MIA lounges listed, I have visited the following four:

1. AMEX Centurion. This lounge is usually packed to the rafters. The food is decent, as is with most Centurions, and the views are nice. However, the insane crowds can be annoying.

2. Turkish (Between Concourses H and J). This is a beautiful lounge. It's probably one of the nicest I've visited in the US Priority Pass Network. The downside, like Centurion, it this lounge is usually very crowded (but can be relatively calm depending on the time of day). If you can score one of the few loungers in the small quiet room, this can be a nice place to unwind before a flight. The food selection is mediocre at best. The bar has a decent selection.

3. Delta SkyClub. We visited this lounge recently on an Air France trip to Budapest. Being used to the beautiful SkyClub in Fort Lauderdale, I was pretty shocked at how spartan this lounge is. It is quite small, seems somewhat dated, and is badly in need of a refresh. The food was even worse than that of the Turkish lounge (although admittedly we did arrive about 30 minutes before closing, so maybe all of their offerings weren't available). Unless this is your only option, it's definitely a pass.

4. LATAM. Best of the bunch that I've listed. When we had to leave the SkyClub due to closing time, they informed us that our Air France business class ticket granted us access to LATAM (if only we had known beforehand we could have skipped it altogether). Seeing as you can't get in with Priority Pass or Amex Platinum, this lounge was much less crowded than Centurion or Turkish (although we arrived around 9pm, so that may have had something to do with it). There is plenty of comfortable seating, and I found the food selection and quality to be as good, if not better, than at the Centurion.

I would say it's a toss up between LATAM and Centurion as to which is my favorite of these four, but with Centurion's almost constant overcrowding, I would probably give the nod to LATAM.