Well, I wash and replace my liner on occasion. So, if the non-removable/replaceable headliner doesn't bother you, more power to ya'.
As for comfort and weight, they are nearly identical. I WOULD say the Qwest is a bit more comfortable but primarily because the cheek pads on the RF are a little tight. Noise levels are subjective.
Don't get me wrong, both helmets are good. However, I have an inexpensive ($100.00) HJC that came with removable liners and a free pinlock windshield. You'd think that Shoei would have included cheap plastic snaps into their ~$350.00 helmets instead of securing the liner with crappy double sided tape...
FYIY, You might also want to check out the new Bell RS-1. Cost wise, it's on par with the Qwest. However, the build quality, ventilation and comfort are much better. Also, the additional transition shield puts the RS-1 in a class of its own.