O.K...9mm as a woods gun/firearm/weapon. From a purely technical standpoint, it possesses the ballistics and penetration to get the job done in most cases (depending on what your job is, of course).
I have used one and didn't feel unarmed. My personal experience leads me to the conclusion that it is a bit too light for my tastes. Either that or I was inaccurate enough with it that my shooting was the failure rather than the caliber (I freely admit this is the most probably reason why I am not 100% on the 9mm). Regardless of the reason, when I switched to any caliber .400 or larger, the failures stopped. Again, maybe it was just my shooting that improved.
Since confidence in your chosen equipment means a lot, I chose to go with a 10mm, .45, or a .44. This is primarily because these calibers give me the warm fuzzies that a 9mm does not. If I had nothing but a 9mm, I carry it and not worry too much.
There is one other thing. With a 9mm, I found myself engaged in a constant search for the 'perfect' projectile. Fast and light, slow and heavy, this load or that, etc. It seemed this was a common theme among 9mm carriers. With the other calibers, I feel no such need to play those types of games. To me, this is another indicator of my comfort in the larger calibers. YMMV.
