re: Cape San Blas/St. George Island

The biggest difference is that St George has multiple restaurants and some convenience stores right at the foot of the bridge/ middle of the island. Depending on where you stay they are just 5-10 mins away. There's one convenience store and I think was a restaurant out on the Cape but I'm not sure these days? The cape has fewer properties overall but they are both going to be similar as far as the amount of people on the beach.

Both are going to be 30 minutes to a grocery store and "town" for other things. St Joseph bay is a clearer bay with legit snorkeling options (scalloping season is over). Appalachicola bay is murky brown oyster water not good for swimming. You could still visit St Joseph Bay while staying on St George though.

There's a state park in both, but I'd say most rarely go as the beaches there especially in the fall are quiet enough.

I personally really like Indian Pass and the first couple miles of the Cape. You are closer to both appalachicola and PSJ, still have the same quiet beaches, etc.