You're only missing something if you don't handload the Super. As you've observed, most common .38 Super factory ammo is no hotter than 9mm. Only commonly available factory load I've tried that approaches the ORIGINAL .38 Super specs is the Winchester 130 grain flat point FMJ - it does just under 1300 fps out of my gun. Most other .38 Super factory loads run 1200 fps or less, and some barely break 1100.

However, case capacity is what gives the Super the edge over the 9mm. Using Unique, you can run a 115 grain JHP to 1300 fps in the Super without getting into the pressures that 9mm +P exhibits. I am pretty conservative (read that WIMPY) with my handloads, so I have not attempted to push the envelope, but I feel very comfortable running the 124 grain Hornady XTP to 1260 fps in my gun. The 9mm just won't do anything close to that with a 124 grain bullet, without putting "smileyfaces" on the brass in an unsupported 1911 barrel.

As to any practical advantage that gives you, it's debatable. If you're trying to strafe a coyote running across a field from the seat of a tractor, the faster bullet and flatter trajectory might be an advantage. For most types of shooting, not so much. The best thing about the .38 Super is, as you say, the major cool factor.