My initial exposure to the 38 Super was sort of negative. Back in the 70s I traded into a Colt Gov. in 38 Super with about 500 rounds of fired brass and the reloading dies. After about a year I traded it off with about 400 rounds of more fired brass and the reloading dies.
In 2009 I bought a lightly used XSE LW Commander in 38 Super from a friend. I was with him in the gun store when he bought it and knowing he did not reload told him 38 Super ammo was a bit pricey. Anyway I ordered a Nowlin barrel with bushing in 9mm (9x19). Advertised as a drop in (stop to laugh here), I did get it fit after some work. I bought new mags but the extractor, springs and ejector worked O.K. with the Nowlin 9mm barrel.
Of course then there was the ammo shortage where you could not find 9mm but 38 Super was all over for a couple bucks more per box of 50 than pre panic (so was 10mm). I also was impressed with the 38 Super. I found out in 86 Colt had decided to head space off the mouth of the case not the semi rim. So I bought 38 Super reloading dies and the 9mm barrel went in the parts box. EGW makes an undersize sizing die which is nice by the way (they also make one for 10mm/40S&W).
Then last year I bought a LW XSE Commander in 9mm so now I have them in 45, 38 Super, and 9mm.
Colt still likes their small diameter 9mm barrel by the way. Here the front of the 9mm compared to the 38 Super.
And I guess a picture comparing 9mm (9x19) on the left, the 38 Super (9x23SR), 45ACP, and 10mm (10x25) would be nice.