I'd take the beefier GPU than saving 20 seconds on a 3 hours COD session to be quite honest. This would only be very interesting in a case where you jump game every 10-15 minutes, which isn't something people do. A few seconds of load time isn't a game changer in the grand scheme of things.
It's not just load times though, but pop in with respect to asset density or quality (draw distance, textures etc).
Conversely, I reckon XSX games have a higher average resolution.