Have shot 8" Smiths and Colts and Ruger (9.5")
Good range toys. Kill critters.
Would not go over 6" for a HD rig.
For years a 4 or 6" 629 was on my nightstand.
Colt 1911 did the longest stink (briefly a P 35).
Now my nightstand rig is an HK P30L
Finally, it is impossible to discuss "generic gun" w/o mentioning Ruger. If one wants all around I would pick G20 with "hunter barrel" which if I recall correctly is 6 inches long. One advantage of G40 is ability to have MOS which is nice option in this caliber (10x25).