Oddly, I was just down there on vacation. Estero is definitely worth playing. Even the last ~6 "holes in a field" play decently through creative use of what I assume were artificially created hills. Tons of water carry if you aren't playing from the red tees though. From the reds the chance of losing a disc is quite minimal. Fairly well marked (except for #1 which might have just been changed, not sure). Some of the walks between holes are a little confusing, either very long or crisscrossing with some other holes. The UDisc map is useful.
Tortoise Run in North Fort Meyers was also worth playing, creative use of just enough trees to create lines, low ceilings, etc., but it's basically unmarked. You will absolutely have to use UDisc, as many of the tee pads are unmarked or even have the wrong hole number. Some of the holes seem to have more pads than just the short and long advertised. There are definitely multiple possible pin positions, but not multiple baskets. Wayward tee shots can make for some tough disc finding if you get into the saw palmetto rough.
Riverside Church can be skipped. It's basically just wide open field, sand pits for tee boxes, and some trees on the edges. There ~9 OKish holes, running along the edges of the property. And ~9 holes that really just play to a basket smack in the middle of a field, although they are long, with up to a 500 foot par 3. #1 is actually quite good, playing into a quite low ceiling green fronted by trees, on top of a berm. It sorta accentuates the disappointment.
I didn't play Bay Oaks seeing as half the course isn't even open most of the day, and the reviews said it was poorly designed anyway.