I was an early adopter of a NANO and never had a single problem until I loaded up a mag full of WWB 115 grain FMJ. I had my one and only issue and the NANO hasn't seen any WWB since. It was a year old this past Thanksgiving.
The NANO is a great gun and the retail prices have come down a lot since they came out. It conceals beautifully either IWB or OWB. It is also a pretty accurate shooter.