Since no one else has replied yet I can compare the GS-R to a QCK heavy for you.
The GS-R is quite a bit thinner than the QCK and my old Zowie EC-1 mouse glided over the surface with less friction because of the smoother surface (same with G502 atm)
The rubber base is a lot denser than the one on the QCK heavy so your mouse sinks in less. Because of this the GS-R feels A LOT smoother as you won't have any inconsistencies in the rubber base. Both mouse pads stay on the table surface without moving around much.
I have washed it by hand a few times without problem and the surface still feels smooth. (No torn fibers on the surface)
I bought the old black version of the GS-R link
The revamped version with the different edges is the one you can buy nowadays and I think other than the edges it's pretty much the same mouse pad.
I have had the GS-R for about a year now and I am very happy with it and have recommended it to other people as well, its a good choice imo