Stronger?
Never heard of a catastrophic slide failure or ruptured chamber/barrel of a P3AT , have you?
The Kel-Tec has been around a lot longer than the Ruger LCP , which is undeniably a copy of the P3AT. Saying the Ruger is better or stronger , just because 'it's a Ruger' is silly. Barrel , chamber and slide dimensions are almost identical. The Ruger has also had a recall or two. Some say the Ruger has more of a grip , but bigger goes against the grain of what makes for most concealable. The K-T is flatter and thinner in the grip , which is good for pocket carry. Accuracy is a moot point with these two. It's not a target pistol , a plinker or even a mid range combat weapon. 7yds is about the max , and most nefarious social encounters happen a lot closer. IMO , it's for sticking in someones ear or under their chin when engaged in a furball.
Had my P3AT for about 7 years now. Like my now semi-retired Back-Up , it's got a few dents and dings from being dropped a few times , but it still runs thru most ammo just fine. If someone offered me a brand new Ruger LCP in trade for it , even up , I'd decline.