weight, thickness, grip length, slide length, capacity
Bingo. A good quality holster is by FAR the most important factor in successfully and comfortably carrying a concealed firearm- even more important than the gun itself.What makes a handgun concealable?
It's holster/belt + the clothing that you put on around it.
Make your outfit fit the gun that you feel you need to carry with you.
I can't add much to what has already been said. But I will say that for me it took more than one flavor of gun finally figure out what works for my situation. Once I realized there is no "Perfect gun for all occasions", it became necessary (and easy, fun, and somewhat expensive) to make some other purchases. Again, this is just what I found out, YMMV! Good luck and let us know what you decide on!
I can hardly tell when I'm carrying my P22 though (it's not nearly as powerful though :/ )