There is a rider in the Scottish CX series who is consistently top 10 (normally top 5) on a Genesis Day One.
I have been at many muddy races where I have wished I had a SS CX bike. For muddy courses you will want a low gear though, as I find it is better to spin in a low gear than mash through mud in a high gear.
I’ve previously raced SS CX on 26er Inbred and wasn’t massively slower than I am now on a proper cross bike – just a few places back. I guess it depends on what your local CX courses are like though.
Overall I reckon you might be a place or two down in each race, but far more likely to actually finish a race without issues.