More weight, wider grip spacing, more volume in the firing chamber for a better shot, and I have noticed my GS has delrin trigger bearings where the Axe uses metal bearings, metal feedneck (GS is delrin), GS has the newer Relay that doesn't wobble like on the Axe if not installed right.
I have shot them both. They both have ups and downs. Properly tuned and broken in they shoot VERY similarly. The Axe will get lower operating pressures due to the higher air volume chamber it has. It comes down to features, what would you rather have? I like the rubber grips of the GS, but still hate the small, cramped feel of it, this can be corrected with a Nummech VLX frame but that brings up the price quite a bit and possibly the pressure. Some people like the tight profile. I didnt like the Axe grip frame, I felt it was too wide front to back, but I have small hands, the GS's is smaller. I found that the 2015 Axe Pro addressed all the issues I ever had with both markers, just wish there was a rubber grip for the front available.
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2015 Axe Pro
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