tbh its the same here, Cubase 10.5 is running the same plugins for the same performance hit as S1 Pro is , i'm seeing the same numbers roughly and there's no massive saving, ASIO guard high or low, and the dropout protection (Which I assume is the equivelent) high or low, I don't see any real benefit of either.
In terms of looks, Cubase wins hands down for me
In terms of workflow, I could easily get used to S1 Pro but its nothing remarkably better than Cubase.
I am attracted by the integration of Melodyne, as I feel that would work better than variaudio but then variaudio is improving all the time too.
If I was given a free copy of S1 Pro, i'd probably switch. But to spend money to make the switch when I really don't have any spare, not going to happen.
But I am really glad S1 works on my system now, and i've had a really fun day using it, i'll continue to use the demo until it runs out, and i'm also really happy to find another DAW that I really do like so if Cubase ever gets too annoying or Steiny make a business decision I really dont like, I have a reserve ready to go.