I bought a Walther P22 on a whim at a gunshow in March. I'd spent a while looking at them.
Positives: The P22 is light, small and in the "fun gun" category. Seems to shoot about anything, but best accuracy is with 1000 fps ammo.
Negatives: I can't shoot this pistol as accurately as I can the other .22's I have. Windage is adjusted as is typical with a plastic adjustable rear sight. Elevation is adusted by changing the rear sight and, therefore is not as precise as handguns with adjustable sights. Casing ejection is weak and goes straight up, in your face or down your shirt. Overall quality may be an issue. At 600-900 rounds, the trigger ears decided to start eating the slide. The pistol is back at Walther for a fix.
Overall: I like the pistol. However, I would not recommend it to a serious shooter, or a first handgun shooter. It looks like Walther could make a better quality pistol. it is not up to their standards for other handguns.