I’m in the ntppool.org pool for the UK. It randomly assigns servers which could be any stratum really (but there is quality control on the time provided). I also have stratum 2 servers in .fi, and .fr (which are dedicated servers I also use for other things, rather than a raspberry pi).
I think people’s experience with PLE will always be subjective. In the old flat we were in, where I needed it. It would drop connection all the time, it was unusable.
But I’ve had them run totally fine in other places. Noisy power supplies that aren’t even in your place can cause problems. Any kind of impulse noise (bad contacts on an old style thermostat for example) and all kinds of other things can and will interfere with it.
Wifi is always a compromise too. But, I guess if wiring direct is not an option, the OP needs to choose their compromise.