I will preface this with the fact I grew up in south Florida and fished in the keys a LOT back then so I’m a bit prejudice when it comes to the keys and the fishing today.
We went to Marathon last year.
The amount of traffic and building down there now, all the way from Key Largo to Marathon, was unbelievable. When we went by Islamorada, there was probably 100 boats on the sandbar on the ocean side. Marathon was almost as bad.
Restaurants were busy and expensive and the food was only ok.
I had 2 half day charters booked, one for yellowtail and the other flats fishing.
The yellowtail trip was a skunk. At one point on the reef there was over 20 boats fishing and this was Monday.
The flats trip was great. We caught tarpon, snook, a permit and cuda.
I wish you luck down there.