Compared to the 9mm, the 38 Super is a larger cartridge able to hold more powder therfore driving a similar sized bullet faster. It is also 30 some years newer so is able to be driven to higher pressures, again allowing for higher velocities. I do not understand what you mean that a "9mm has to be driven harder to keep them straight" but i find the 9mm to be more than accurate enough for its purpose. The 38 Super has been kept alive by target shooters for years so many of the guns for this caliber should be more accurate than the run of the mill service gun. As for stopping power, the .357 mag was designed in large part in response to the .38 Super. With good bullets I don't think there is much difference between the two but the .357 mag is generally the milestone all other cartridges are compared to (some will say the .45 ACP but I don't agree). finding good defensive ammo for the .357 is easy here but the choice in .38 Super is very slim. I've shot a couple 1911s in 38 Super and found them to be very accurate but no more so than several .357 mag revolvers I've owned. At about 1/3 the cost of the Supers they were great deals and putting just a little of the money saved into improving the gun would likely make them out perform the 1911s.
