I have one, and haven't really got a complaint on it, other than that I really haven't found a round that the heavy recoil spring works with. As long as you clean it (which some people neglect on their .22s, and expect them to function flawlessly), and feed it quality ammo (not "bargain bin" .22 ammo), it functions fine. Mine likes copper-washed .22lr, and has functioned fine with anything that doesn't come out of the box with bullets that are wax-coated or turn in their casing (i.e. cheap promotional loads from the various companies). Keep in mind, it's a SIG semiauto .22, not a "feed anything" shotgun. It's not just a "feed any worthless .22 ammo I come across" type firearm. Mine really likes CCI Minimag, and some Remington Golden Bullet (THAT suprised me), and hates all form of plain wax-coated bullets. Minimag ammo is still about 2/3 the cost of 9mm, and you get 100 rounds instead of 50 in a box. Keeping the ammo cost in such relative terms--its a bargain. And at the whole 90% size of a 226, it's gotten me very interested in that firearm, as well.
Keep it clean, and don't feed it crappy ammo, and you should be fine. They don't have cheap, worthless "brand promotional" loads in Europe, they have good quality ammo only. Plan accordingly, and keep in mind what the thing was designed around.