Had my P22 for three years. It is the one gun that is going to the range every time I go. It is permanently in the range bag. I have shot thousands of "cheap" .22s in it. I have never shot anything BUT "cheap" .22's in it (Wal*Mart 550 for $10 Federals)
PLUS- I shoot all the loose .22s I find on the ground at the gun range through it. I found about 600 last year alone. I had a Cool-Whip tub full of "dropsy" .22lr's and shot most of them one day just to see what would happen. Some are pretty crusty looking. About 10% of them don't fire at all, some take two or three strikes to fire, assuming I can jam them into the chamber, some of the lead bullets are munched up from previous misfeeds by other people...had one take half a dozen striker impacts to finally fire and when it did the case rim failed at a previous striker dent and showered me with smoke and burnt powder residue. Gun was fine.
I have not cleaned the gun in almost 2 years. I am letting it build up crud to see what will fail. I inspect it pretty closely. I had to switch magazines last Fall due to so much black residue that it would not feed reliably. The gun feeds just fine.
I would say I have close to 5k rounds through mine.
I oiled it heavily when I first cleaned it. It loosened up fine as it broke in. I have had no problems out of it.
It is a blowback .22 and yes the slide is zinc. It handles and has the same manual of arms as a "real" pistol (slide moves, etc). It's a great trainer to get someone used to a real gun before moving up to a bigger caliber.
I have heard of fractured slides failing at the front. Most of those are the 5" compensated models, the slide batters against the compensator (which is a fake useless thing anyway). Also people who use a lot of high powered .22's seem to be having the problem. People who never used Stingers or Velocitors or anything snappy are not having the problem.
The early style magazines (that have no -A- in the part number) are problematic feeding sometimes, but they changed the design and fixed the issue. Any -A- magazines are good.
Accuracy is OK, it's not a target gun with a 3.4" barrel, but at 25' if I do my part I keep them all in a standard target.
I like it better than my 22A S&W. I like it better than a Sig Mosquito. Plus it has a threaded barrel, so if you want a supressor it's an easy thing.
Not knocking Ruger Mark X or the 22A or the Buckmark or Woodsman. Great guns. But I like my Walther and everyone who has shot it does too.
Not a great self defense gun. Just a fun plinker.
I'll second xrayguy. Anyone who wants to dump their "terrible" p22's, let me know. I'll pay $100 plus shipping & transfer fees for any P22s that need new homes.