[halfmoonclip]

Concur with Ranger; if you must have a wear-proof finish, hardchrome is the stuff, and it looks good too. You don't have the hassle of shipping a gun if you only ship the slide/barrel. Metalife in Reno, PA has done nice work for me.
But I don't worry about it with Glocks. I never toss them on track ballast, but a little wear hurts nothing. There are fancyschmancy guns that have no holster in this house, but there is no shame in using/abusing a Glock.
Moon

 

[halfmoonclip]

leather', it may depend on the issue, how you present it, and who picks up on the other end.
I had a 42 & 43 with the 8lb triggers, and finally made an issue of them being out of spec with the rep I talked to. Out and back in a week. YMMV.
As regards Glock finish, Glocks are fugly right out of the box, and a little wear doesn't really signify. It's not like a pretty blue or nickel gun.
Moon