I have the Nano and the .40 cal shield. I am basically happy with weapons but the first few months with both were a pain in my, well you know. The Nano flat refused to run 115 grain ammo. It would fail to eject and jam. Running anything bigger 124 or 147 was no problem at all. After running around 500 rounds through it, I tried the 115 gr again and it has run just fine so far. The shield has had its issues as well, it keeps ejecting the extended round magazine and the front site is off. I have sent it back to SW for repair. I am still using my faithful MP360 as my carry pistol. I may only have five shots but at least I know it is reliable. Since its recent reliablity on the range I have added the Nano back to the carry lineup. We will see with the shield once I get it back.