For what it's worth, our Monaco came with a factory installed Magnum ME2012. This is a 100 amp 3 stage charger with a builtin 2000 watt MSW inverter.
We've never had a problem.
Everything we plug into it works just fine. Clocks don't lose time, fans don't hum, Apple products don't go up in smoke.
And at least at Magnum, PSW inverters cost more than DOUBLE MSW's.
I personally believe PSW is nothing but advertising hype.
But then, I do not believe climate change is primarily caused by human activity either, nor do I accept that their is anything humans could do to change it.