I own both, rather, owned both. I returned the Mosquito after my first range outing (one good thing about being a regular customer at a small store). It jammed, failed to feed, failed to eject, stovepiped, failed to lock the slide on an empty magazine and locked the slide with a magazine with rounds in it. Couldn't see a pattern to the malfunctions and I wasn't able to shoot an entire magazine without some sort of malfunction. The longest string was 6 shots. I put through over 400 rounds of various .22lr that day. Even CCI Mini-Mags didn't work well with it. My 87T has over 10k through it. Not a hiccup from day one. Eats any ammo I put through it. Reasonable accuracy, reliable and fun to shoot. I say reasonably accurate because my Ruger MkII Government Competition is a more accurate pistol in my hands. My Beretta 87T hasn't disappointmented me nor failed me, the Sig Mosquito did both the first time I had it out. YMMV.....