To be honest, I think it's just who has the most recent design as to who's leading the market. The big point for the Taurus was the fact that it has a last round hold open. Which is nice, and is my biggest complaint about the LCP. My initial reaction is to try and clear a F2F before actually thinking about a mag change (I can't count when I'm shooting.)
For readers of the earlier post, the LCP does have a slide stop, so it can be locked open. Trekbike was referring to last round hold open. I only bring this up because I do have a pocket pistol that does not have a slide stop at all. If anyone is familiar with early .380s, the LCP is head and shoulders above anything produced 25 yrs ago.
I do like the TCP for the better sight picture, and their trigger guard does have a better design, but I'd doubt the actual recoil is much different than a LCP or 3AT. Being fair, I haven't shot one yet, but I'd have to believe it's perceived recoil. Any light gun of this size in .380's going to be somewhat violent.
If you are in the market for a pocket pistol also check out the new S&W Bodyguard 380. The price is only slightly higher than the LCP or TCP and it has a laser integrated into the frame. It's also got blade sights comparable to a traditional pistol.
IMHO, the laser's more valuable than sights on any of these guns. I regard these as point shooters, and suggest training accordingly.
The LCP is my every day carry gun in a desantis nemesis pocket holster. If you carry this way, expect to do some spot cleaning on a weekly basis. You'll get lint in the barrel, trigger, hammer opening and have to oil the outside of the chamber/ejection port/ (whatever the proper term is). I have let the LCP get about a months worth of dirt on it and then spent some time with it on the range. I've yet to have a malfunction out of this gun clean or dirty. Next purchase for this gun is a SofTuck holster. It should help with the lint issue, and I'll be able to put my keys in my pocket again.
If I could carry a duty pistol every day I would, but if you have to wear a suit or shirt and slacks it at least gives you a defense option without making the sheep (and HR) nervous.
Sorry for the long post.