I have a Sig Mosquito, which is essentially the same gun as what you are looking at. It looks like a Sig, but the internals are nowhere close to a "real" Sig product.
Mine was picky about ammo until I buffed the feed ramp w a Dremel and since then it has been fine.They don't have a great reputation, but a search on YouTube actually turned up more positive than negative reviews. Given the choice between a RugerSR22 and a Mosquito, I would pick the ruger.