Very nice, I'm glad to hear you're satisfied with your purchase. It sounds like you got a pretty good deal there. I got a barely used 3rd gen Glock 17 with night sights at a local gun store for a bit over $400 IIRC, so you certainly didn't get a bad deal.
Although some folks who don't bother to even read posts or look at evidence (Or even try the thing) will tell you it doesn't make any difference, consider snagging a DPM mechanical recoil reduction system for your new Glock. The system consists of a stainless steel guide rod and a dual recoil spring setup. It made an unbelievable difference on my Glock 17, it's the best $70 I ever spent on an accessory. I honestly wouldn't own a handgun for which the system is made without it now. Don't worry about the haters who don't even read posts btw, tighter double tap concentration wont make you less of a man. :P