Not much of a difference. The biggest differences are the p22q no longer have a trigger lock and Walther improved reliability. I own a Walther p22 and while I really like it it's pretty picky on ammo, so Walther improving reliability is a huge improvement. I'd personally go with the Walther p22Q because it's pretty much just an improved p22. Hope this helps.

James, They are essentially the same. The Q has different stippling on the grip, different grip surfaces on the slide, and no lock. They price out within a few dollars of each other. I have read that all bugs had been worked out in the last few years so I would not hesitate to buy either one. The P22Q seems slightly more accurate compared to the P22 with the youtube reviews I have seen. Cheers and stay safe!