The .38 super is an uploaded version of the old (John Browning designed) .38 ACP. Factory loads are definately more powerful than a standard 9mm. IPSC shooters like it because it can be handloaded much hotter than that. The common lopading of 130 gr FMJ is inadequte for defense. The Winchester Silvertip load is a 125 gr bullet at 1240 fps. No slouch by any stretch. Corbon makes several loadings, but I cannot find the exact ballistic info. Generally they are hotter than most other makers. Federal makes a 115 gr HP.
I want a .38 Super, but not in place of a .45. If I could only have one, it would be a .45. Proven fight stopper and more commonly available ammo.