Picture of me knocking down 4" squares @ 35 yards at Sportsman's Team Challenge Nationals.
Not sure exactly what kind of comparison you're looking for but I've been shooting 38 Super since 1994 with a total rounds downrange count of over 150,000 rounds (the majority of which were handloads).
Factory ammo availability quite definitely goes in favor of 9mm.
Factory ammo price goes to 9mm.
Reliability in 1911 style pistols (I personally prefer 38 Super) I can elaborate if you'd like (send PM or better yet, give me a call 318-949-9884 & ask for Renee)
Making major for USPSA/IPSC Advantage 38 Super
38 Super is Semi-Rimmed and has a much larger case capacity than 9mm.
9mm in the middle
9mm: Overall length 1.169" with the case length normally 0.754." Typically, this rimless cartridge measures no more than 0.394 at the rim. (Rimless simply means that the lip of the rim does not extend wider than the case.) Just above the extractor groove, the case is no more than 0.391" wide and tapers to 0.380" at the case mouth. 33,500 to 34,000 PSI range
.38 Super: Same pressure range as the 9mm. Non-tapered case measuring about 0.384" wide and 0.9" long at the maximum. It is a semi-rimmed cartridge and the rim is approximately 0.406" wide. The cartridge is loaded to a maximum OAL of 1.280." Similar to the .45 ACP OAL of 1.275."