I recently sent in a early production (1988) G19 for the upgrade that hadn't been done. I picked it up at a gun show a few weeks ago. The gun looked new, and had night sights, but both mags were cracked. Anyway, I sent it in for the upgrade and tossed the mags in just in case they felt like replacing them. They said turnaround would be 6-8 weeks, but I got it back in less than two! With 2 new 15 rd mags With the shiny new parts inside, it's pretty much a new, old Glock. The trigger seems a touch heavier than it was before it went in, but it's super crisp and not all mushy like my 26. Anyway, I've heard lots of good things about Glock CS, but experienced it first hand. I'm a happy glocker.