FWIW:
VS coach is definitely more cramped than CO coach!

I couple of years back, flying EWR-LGW on a DC-10, our CO flight had rudder problems and we returned to EWR.

Within a few hours we were on a VS flight, 747 I recall, where I could make a direct comparison on the seats. CO felt much roomier in terms of Y seating than did VS.

For a long haul in Y, I'd suggest CO over VS for seating, though you do forfeit the perceived fun/coolness of flying VS.