I had a mosquito before and a full size P226. I prefered to have 2 different pistols as 22lr is really dirty. I then picked up a nice 226 classic from EE and ditched the mosquito.
Compared to a 226, the mosquito feels like a toy, it is made of plastic, it's light and very small. Perfect size for GF or kid imo; I have small hands, and the mosquito felt really small in my hands.
The only nice thing about the mosquito, is the "proper" functions; the slide locks back on empty mag, which the conversion or classic doesn't do. I bought some parts from jeffsig over at sigforum to fix it (It locks the slide on the mag follower, not with the slide stop).
All in all, the sig 226 classic if a better option vs the mosquito in my book as you train with a pistol same size with the same trigger.
On a side note, I had much less malfunction with the p226 classic than I had with the mosquito.