The RC fit 1/2 size bigger.
I picked mine up at the RC vancouver store and we got to try them on. Everybody went TTS or 1/2 size down depending on the fit.
IMO they fit similar to UB 1.0 Wool Greys that I have (Wool greys fit bigger than 1.0 triple whites / creams)
The RC primeknit is thinner...