I should have thought this was rather self-apparent.
Huh. It had not occurred to me to think that this would even be a question.
The .32 acp (7.65 X 17mm Browning) is a .312 caliber bullet, traditionally of 72 grains, at about 905 f.p.s. for a whopping 129 foot-pounds of energy.
The .380 acp/9mm Kurz / 9 X 17mm / 9mm Corto / 9mm Short is a .355 caliber bullet, traditionally of 95 grains, at about 955 f.p.s., for a more considerable 190 ft/lbs of energy.
Let's see: Bigger bullet? Check. Heavier bullet? Check. Faster bullet? Natch.
But what really seals the deal in favor of the .380 acp as a better round is the absence of the completely befuddling semi-rim on the base of the .32 acp. While the .380 has a "rimless" style cartridge case that does not project any rim beyond the line of the case walls, the .32 acp has a very tiny rim protruding out beyond the case walls-- on the order of .0105" beyond. This surely was to aid in headspacing and extracting, but also can interfere in functioning, causing rim lock, occasionally, when not loaded carefully.
The .32 is available in some amazingly tiny pistols, and that's really its greatest claim. It is quite a bit more powerful than the anemic .25 acp, but despite the popularity of the James Bond flicks, the .32 is no powerhouse.
The thing that makes me scratch my head is: how the HELL could anyone consider the .32 acp as a better cartridge?
Maybe they were thinking .32 H&R Magnum?