JR, I have shot my G35 and G19 in IDPA and Speed Steel, non-sanctioned. The G35 seems to dip when the slide returns to battery, even with a 15lb recoil spring. The G19 seems to buck a little more than I would like when the slide reaches full recoil. I'm looking at installing a G17 complete upper on my G35 frame. Is there a big enough weight difference between the G35,G17/22,G19 slides to effect the felt recoil and cycling? Thank you, Lucas P.S. Anna in customer service was a great help when a certain delivery company lost my order.