I just bought a Gen 4 G17 and put 200 rounds through it, flawless. I dont have the largest hands so the grip fits nicely. I've been very excited about the Gen 4 SF models because of this. After 100 rounds I found the side panel grip texture was wearing too aggressively against my support hand. Probably since I'm a pencil-pusher but a little bit of 400 sand paper tamed it just enough that its not an issue. You can really tell the increased strength of the new recoils spring assembly because the resistance is noticeably stouter than the gen 3 design. It reminds me of a hand fitted 1911 versus a stock version. Its funny because its so tight that it makes my G21SF seem very sloppy. My one disappointment is the trigger pull weight. Clearly, its heavier than the Gen 3's as I compared them to two of mine. Its about a pound heavier. I experimented with "-" connector which lessened the pull weight but it lost its clean break. I personally have not ever liked this connector in any setup because IMHO it seems "mushy" and not clean like the standard connector. That's just been my experience. So, I am open to ideas on how to get a gen 3 stock trigger in my Gen 4. Just rambling on. Overall I really like the Gen 4 design.