It has been my personal experience that 7.65 PPKs are pleasant and reliable, while .380s are not.
It feels like the slide is clanging on the frame at every shot in the .380, and it is distinctly unpleasant to shoot.
(Before I get any accusations of wussiness, I'd rather shoot magnums in my 340 than .380s in a Walther!)
Balistically there is no huge disadvantage with the .32.
Best,
Moon