I own one in a QA version. 3rd Generation with the extended mag release.
Trigger action on mine was horrible 'till I followed some relatively simple mods. Unjustifiable for $1200 gun, though...
Only other issue I've ever had with it is blowing apart four mags within 2 hours during a PPC course last week. The .40 10-rounder mag is equipped with a baseplate which is very fragile. I've owned this pistol for a year and have fired no less than 2-3 thousand rounds thru it. Never an issue.
Slapping in four of my five mags (the four that I was using in the course) is what blew them apart.
I've talked to Earl of Earl's Guns in the states, he's considered to be pretty up to date on Walthers. He says it's an ongoing issue and that the mag baseplates need to be made out of aluminum in order to fix the problem.
Which I what I'm gunning to do now. Looking for a machine shop to do the work.
For what it's worth though, I do love the gun. And the AS version has a great trigger outta the box. I owned one as well awhile back..