Biggest issue I can think of is trying to do PWM _and_ WiFi work simultaneously on an esp8266. If you have, say, an esp8266 serving up a small webpage for control and don't want to add an external PWM board then you might notice intermittent issues. This is more obvious if you're controlling something like a lighting ballast that's PWM controlled.

Of course now that I'm looking around I see https://github.com/khoih-prog/ESP8266_PWM which seems promising (subdivides the second of two available hardware timers to allow PWM that isn't sensitive to other running code). So there's multiple workarounds (libraries, breakout boards) besides upgrading to an esp32.

Depends on what you do. Few years ago I played around with micropython on a ESP8266. There a bit of extra RAM would have been helpful. As said years ago, can very well be that micropython is better optimized nowadays and it's less of an issue.

That YOU have found. I use both and for sure the ESP32 is now much more favoured in my setups than the ESP8266 (as much as I love that chip).

I’ve wanted to try out the ESP32 for a while but I haven’t yet found a project that the ESP8266 couldn’t handle. Love that chip.