Yeah I have tried it! It beats WiFi to some rooms, but to my office it's very slow.
You would never be able to predict this, which is an unfortunate thing about powerline IMO. You just have to buy the modems and see how they perform on your particular wiring.
And how stably. Ours works amazing if you ignore that it duplicates packets 2-3 times for no reason (netting a few hundred megabits, many times the speed that VDSL is able to deliver here), but then it will die for a few minutes roughly once or twice a day, unpredictably. Thankfully we only need it for the bedroom and everything else reaches from a centrally hung 'router'. When it's down again, we briefly switch to mobile data or the poor signal we get from downstairs or we, y'know, get out of bed or turn off the phone and go sleep, depending on the time of day :-)
It's a strange pattern and I'd be interested to solve the mystery. Not many powerline debugging tools available though, not to say none