I read Nextville and a lot of it is pure BS. the author says that much of what she talks about is based on information fed to her by third parties. Panama was "discovered" a few years back when Costa Rica started to get too expensive for American retirees. Housing is no longer cheap in Panama but there are many advantages to retiring there. Panama City is a beautiful, modern city but it is a sauna. My son lived near there for 7 years when he was in the Air force and I visited him there and have also been there on business. At one time we were considering retiring to Panama (my wife's ex is a Panamanian involved in real estate) and if we did it it would be in the highlands where the temperature is moderate and you have quite a few expat communities, but it is pretty remote.
If you are serious about Panama do your homework and don't go by Corcoran's book.