mox - the 9x23 case is basically a rimless 38 Super. The 38 super is a semi-rimmed cartridge and much of its earlier lack of accuracy was due to its small rim and the fact that the major manufacturers of handguns in that caliber made their barrels to headspace on that small rim. A few custom barrel makers, Bar-Sto for example, made their 38 Super barrels to headspace on the case mouth, allowing for much greater accuracy.
Those who rant may not just be ranting. The 9x23 Winchester is a factory loading of what the 38 Super can and has been reloaded to - a 125 gn hp moving at 1425'/sec. My Lyman 43rd and 45th editions list 7.7 gns of Unique under a 130 gn slug for a max load for that bullet weight and the 125s over that loading chrono at 1425'/sec. The 9x23 Winchester is one hot number and if the mistake is made to chamber that round in an older 38 Auto (same case dimentions as the 38 Super) pistol there could be trouble.
There are other 9x23 cases out there that are of european design: the 9mm Largo, 9mm Export, 9mm Steyr, 9mm Bergmann and 9mm Bergmann-Bayard. The casings can be used if found to be reloadable but most are not. Many of these rounds are loaded slightly longer than the 38 Super/9x23 Winchester and although they will chamber they may not fit well enough into the magazine.
I believe the 38 Super is 22.9mm long and the 9x23 is 23mm long but I think that may be the difference twixt the semi-rimmed and the rimless designs. The 9x23 may actually be a stronger case design. As previously mentioned, I have shot factory 9x23 Winchester from my 38 Super barrels and mixed 9x23s and 38 Supers in the same magazine with the same harges and bullets and never knew the difference when the gun went off. Functioning was flawless. Mikey.