I have both Glocks and Walthers
G20C, G29, G17, P99.
I love the 10mm's; I inherited the G17; bought the P99 it was a police trade in, carried a lot and it has a lot of wear and tear. Put new night sights on it because the old sights were beat to hell. It fits better, carries great, and it is the most accurate 9mm I have shot, that is a duty pistol.
I bought it for my Son in law, but he liked my Browning Hi-Power better, it was tricked out by Cylinder and Slide.
I can't complain, he carries it daily to protect my daughter (she carries my Colt Lightweight Combat Commander Series 70 in .38 Super) {she is scary good with it too} and grand kids.
The P99 accuracy wise is tough to beat. The only bad about the P99 is the trigger is a little sloppy.
EDIT - I reread your question, my P99 was not treated well by the previous owner, grip area and sights were beat to hell, and scratched to hell and back, it looked like it had be dropped and thrown around. The metal work and finish was in good to better condition, no rust or scratches. Lockup and functions good to great. With the beat to hell sights I was able to keep 3 magazine dumps in a 6" bullseye at 50 yards.
So that was the decision factor, it functions good and shot great. Cleaned and greased it. Put new night sights on her.
My shooting buddies give me a dump truck load of shit about carring a beat up POS looking gun, but when it comes right down to placing a bets against me shooting it verse any other gun I get no action. I have to find other suckers that don't know me or that gun.
So in answer to your question if it fits your hand better than a Glock, and you can shoot it better. Buy it...
I don't think anybody can wear out a newer production handgun these days unless you are Doug Koening, Or Jerry Miculek......