Found a used or police trade-in Glock 20 in a local shop for $389. It has no box, 1-15 round mag and seems to be in great shape, just light finish wear on the slide. The lack of finger grooves means that this is a 2nd generation Glock 20? IIRC, there were no 1st Gen. G20's, correct? I have read that many people prefer the 1st and 2nd gen. Glock over the 3rd, is it just because they don't like the 3rd gen. finger grooves? Is there different/better on the 3rd gen. G20's besides finger grooves and a rail? It seems like a decent deal, but with no box and 1 mag, maybe it isn't that great? Thanks for any help.