I have one and love it! It has been my favorite “kit gun” that I always take along whenever I go shooting no matter what gun I am shooting mainly.
I experienced some “FTFeed” and “FTExtract” during the initial break-in period, especially with one of the magazines that came with the gun. I sent the bad magazine back to Ruger and they sent me a new one promptly. While I was waiting on the replacement mag, I also polished the tiny feed ramp and other very sharp edges around the chamber with #1000 wet-dry sandpaper.
Now after about 1,500 rounds of various ammo, my LCP-II 22LR has been as reliable as the little gun can be, so long as the ammo goes bang. (In other words, misfire is the only issue I occasionally experience, mostly with Winchester ammo.) Mine seems to work most reliably with high velocity ammo from Federal (i.e., cheap BYOB and value pack ammo) and Aguila, as well as CCI Mini-MAG.
Ruger told me that we can shoot hyper velocity ammo such as CCI Stinger and Velocitor through this gun on a regular basis with no problem. My favorite hyper velocity 22LR ammo is Aguila 40gr Interceptor, and I have not had any reliability issue whatsoever with this ammo, though I have had a few hiccups with Stinger and Velocitor.