I started testing and comparing now. M1 MacBook 16GB vs. my i9-9900k Win10 desktop. So far it is very impressive. Cubase runs without problems, lots of FabFilter/Waves/Slate and other plugins, Superior Drummer 3, guitar and bass amp simulations etc.
Only FabFilter is silicon supported so far. So I am almost sure that the performance will be mind blowing when Cubase and the rest is native silicon as well.
BUT: The biggest source for problems is the eLicenser! It loses connection to my USB licensers all the time.
I’ve run Vienna Ensemble Pro 7 so far once successfully, after trying to start it several times, but not succeding due to problems with the eLicenser. That one time it worked well with some Kontakt instances loaded. Also, the connection to Cubase was established.