i have an old CZ-70, that I like. It is .32ACP and I'm always hemming and hawing if I should get a newer sub compact in 9mm. The dimensions are basically the same, weight is the same when loaded ... so, what am I gaining? Sure, the newer pistols of the same size are 9mm vs. 32ACP, few more rounds with the fancy magazine designs, but I can't shoot them as well, and follow up shots are way slower. I end up back to, well - shots that miss, or don't get down range in time are of no value - so, I'm not really sure what I would be gaining, other than following a trend that makes little/no sense to me, since you have to actually be able to hit targets and quickly, and follow up ...so, maybe others can make it work, but I haven't been able to figure it out.
I'm not timing myself, but it feels 2 or 3 times slower when I use some of my friends moderns sub compacts to make follow up shots, but - everyone really seems to like shooting the old CZ and take to it rather quickly. I've looked at the ballistics of the Fiocci ball ammo I carry, and for me - since I fully expect never to use it - and in the summer downgrade to an NAA mini revolver with .22 Mag, I'm good with it.
Some manufacturer will figure out a slightly hotter .32ACP like they had for the Frommer Stoppe - or whatever it was called, in a modern firearm with a 3.5-4ish inch barrel, with one of the fancy half double stack magazines to get more rounds in there, would be competetive in a sub compact size, like a Walther PP or PPK size little handgun. They've had the velocity up around 1,200 fps before, and the nrg curve goes up dramatically, and hollow points certainly will expand at that velocity. Just some musings, don't think it will ever happen. Maybe someone already makes one and I just don't know it.