Never ridden a Kass, but C2BTX is really fun to ride (got to ride a TRS). The base is GNU's sintered base, which should be fast enough for whatever you want to ride. I have a 2009-10 GNU Carbon Credit and my topsheet is in fantastic condition despite the lift line's best effort to hurt it. It'll be covered in snow anyway so who cares.
Malavitas are my second favorite binding next to the Atlas. You're gonna have a great time, man.