I have had my gen 4 for a while but I have not shot it much, I pretty much picked it up threw in a ghost 3.5 connector and a trigger spring and tossed it in the safe. The only reason I got a gen 4 is because I got it at dealer cost through work, it was a LEO gun with factory nights. I have only put roughly 400rnds through it and it definitely seemed tighter and less smooth than my other GLOCKS but I just wrote it off as "being new". This weekend I met up with John Wolff (john the GLOCK doc) at a local gun show, I have know John on a "at the gun show" type basis for quite a few years, He asked me what I was carrying today and I produced my gen 4 after a roll of his eyes he dry fired it and said "what the hell, do you have the NY spring in it ?". He instantly tore it apart and replaced the spring and connector with the OE 3.5 connector and the OE "competition" trigger spring.............. It was like night and day, apparently non OE connectors do not function well in gen 4 guns The OE stuff was smoother more crisp and lighter !!