I believe (maybe naively) that 90% of the wildly different responses we see re:AP/FSD performance are simply local road conditions.
Some people (accurately to their own experience) grade it A+, perfect, ready to go.
Other people (also accurate to their own experience) grade it a C- at best.
You have just experienced both back to back yourself, and if Key West was your daily drive you would be re-considering why you spent on FSD, whereas previously you would have probably thought those on the other side to be a bunch of whiners.
Would be interesting to see someone crowd source a geolocation DB of AP/FSD performance!