Several years ago I looked at both. I shot both. I bought the Ruger, at a higher price, simply because it looked better, felt better, and most of all, functioned better. While I am sure, like the Kel-Tec P32 I have, the P3AT would have eventually "broaken in", and been the 100% reliable that the Ruger has been from the verry beginning. But why wait, and hope. In fact, the P3AT I shot is still owned by a friend, and after a couple hundred rounds did start running better. Not 100% with any ammo like my Elsea Pea, but it hasn't failed with good quality SD ammo.
So I would say reliability out of the box was a big improvement!