With today's premium and high velocity ammunition, barrel length and caliber are less of a concern than they were in the past. +p and +p+ in 9mm, Corbon, Triton and Doubletap in .38 Super, .40 S&W, 10mm, .357 SIG, and .45 ACP & GAP, along with the designs of the Gold Dot, Golden Saber, Nosler, Hydrashok, Starfire, etc. yield hollowpoints that are moving fast enough to reliably expand and penetrate under most conditions, and with enough different bullet weights to match, with most barrel lengths. If reliable performance, i.e., expansion, is a concern for you, remember that, generally speaking, a bigger bullet that doen't expand is a better choice than a smaller bullet that doesn't expand.
Accuracy: can you hit a 7 in diameter size target at 25 yards consistently......
Can YOU hit that target consistently? If the shooter does not have the skills &/or doesn't practice to do so, no pistol is going to make up for his deficiencies.
With all of the above in mind, I carry the following on a revolving basis, depending on what strikes my fancy that morning: S&W 1006 10mm, S&W Sigma .40 VE, Kimber Ultra-Elite .45 ACP, Colt Delta Elite 10mm. All are carried in a Milt Sparks Versa-Max II IWB holster; with its attachment locations offset, it helps to distribute the pistol's weight & stabilize movement of the holster. I only recently (within the last month) started carrying on a Milt Sparks 1.75" wide, double-thick gunbelt. The difference in comfort was clear & surprising to me; I thought the belt I used before was comfortable enough-I was wrong.
With all that said, the most comfortable of my carry guns is.....my lightest one, the Kimber Ultra-Elite (now called the CDP). It is 24 oz. unloaded, holds eight rounds (with a Chip McCormick Shooting Star magazine), and has the Officer's length frame. More mornings than not, this is the pistol that strikes my fancy. That's what works for me.
Regards,
Sam