If you have a choice, I would suggest the 3.5" barrel over the 5" P22. The longer pistol is not measurably more accurate, less handy and a good bit uglier. And it will never match a Ruger MK of any kind or a Buckmark for target shooting.
The little gun, even with its pot-metal slide, finicky taste in ammo and lately inflated price tag, is really a lot of fun. Mine has digested 5,000 rounds with nothing but regular cleaning.
I've read about breaking slides, crappy mags and horrid accuracy, just never experienced any of those myself.