I got a chance to shoot my new Gen 4 G21 today! Love it! While the day wasn't perfect the pistol performed well and only gave me a couple of very minor issues. I am still very pleased with the Gen 4 21. First the range was blocked up most of the day with a CCW class, so it took a while to get on. Once we were on the range I loaded up the mags and noticed that last round is a bear to get in there, but after loading them a couple of times they are starting to loosen up. I figure after a few loadings they should loosen up, but they were still tighter than what I am used to. Anyway I step to the line and fire off the first few shots and on the first shot I get hit in the forehead with a spent case . It left a black smudge I was able to see in the bathroom mirror later, so right off the bat I'm thinking "Oh man I'm going to be fighting this BTF issue all over again", but of the 125 rounds my wife and I put through it only that one hit me in the face. All in all I say the gun performed pretty much flawlessly. The rattle I noticed while I was inspecting the gun after purchase is a non issue. I think it just has to do with the fact that the 21 is a larger gun than my 9mm's and therefore has more clearance. It didn't seem to effect anything at all, and was probably just a bit of paranoia on my part. I may look at some other 21's in a display case somewhere and see if they are the same way, but really I just need to get over it and shoot the thing. Speaking of which I think the 21 is a great shooter even though I couldn't do much with it this go round. I felt I had a bit of a caffeine shake today for whatever reason. I believe the pistol was doing its part, and if I really concentrated I could put the rounds close to where I wanted, but I just don't think today was my best shooting day. The pistol is a fun one to shoot! I found the recoil was muted, but I still knew I was slinging some big bore rounds downrange. The grip is still large even with no back strap on the pistol, and that fact sometimes caused a little confusion in where I was wanting to place my off hand, but it is still (for me) comfortable, and the wider grip spreads out the energy from those big 230gr slugs. As with all Glock triggers I think they are like fine wine, they get better with age! The trigger was crisp, and there is nothing wrong with it, I just think it will be better in about 500 rounds. Bottom line, I think the Gen 4 G21 is rock solid, and super fun to shoot! If I can find (and afford) ammo, I'm gonna shoot the snot out of it!