The only two complaints I have about the GSR:

1) The factory STEEL magazines "wobble" in the magazine well.
2) The barrel isn't chrome lined, and I think many people will use their GSR's as "hard use / survival guns" that would benefit from chrome lining.

A stainless steel version would solve #2, and I've been told the newer plastic mags solve #1. I would not, however, want the plastic mags since they're completed exposed below the rifle and thus subject to impact (for example: going prone hard and fast).