I have a Sig P226 9mm and find the Mosquito fits quite nicely with it when it comes to range time.
I've been through several of the 'other' 22's and agree that the Mosquito deserves better press than many have given it. I too found that if you follow Sig's instructions it not only works but works well. My last outing at the range consisted of 300 rounds of Remington Golden Bullets with absolutely ZERO malfunctions in slow and fast fire. I've also found that time spent with the Mosquito has caused my accuracy with the P226 to go up considerably. My groupings have probably been cut in half as a result. Plus the Mosquito has a very high cool factor since its a scaled down version of the full size with all controls included and where they should be.