No, it doesn't (although the ST120 is big enough it doesn't acclimate instantly, either). And the ST120 is much better on double stars than it is on planets. Nonetheless, as someone who has both, I can safely say the C6 pretty much destroys the ST120 on planets.
It's not that the ST120 is that bad, but the C6 is actually really good. I think SCTs are easier to manufacture in small sizes so the smaller ones are more reliably good. Between the extra aperture and the no CA and having a good focuser out of the box, the C6 is just the superior planetary instrument over the ST120. But it can never get the nice wide fields the ST120 can (not even close!) so it's not like it is superior all around.
I thought one of the virtues, the advantages of any size refractor was that they did not have to climatize like the other types of scopes ? Thats what I have found with all of my refractors vs my several reflectors and an 4se I used to have.