Not sure why the LCP shoots so well.
I had a P3AT awhile back and I don't remember it being anywhere near as accurate as the LCP. A couple weeks ago I fired a friend's TCP and it shot really well, like the LCP. The trigger reset issue was a no-go for me though.
The thing that pushed me to the Custom was the sights, although some guys tell me their LCPs with the bumps shoot just as well.
