I attended a TDI seminar in West Union, Ohio last weekend. During the three day course I fired nearly 800 rounds with my CW40. I was as accurate as anyone using the 9mm in the first two days, but must admit the 40 beat my hands really bad. On the third day it was hard to hold onto the gun properly.
One of the instructors lent me his P9 to finish the day, and it performed perfectly, but with seemingly much less "force"
IMO given a choice if faced by a drugged up gang banger I would chose the 40. If I had the funds and was punching paper I would have the P9 also.
IMO any pistol is better than none.