I carried a Walther PPK/s for many years, during hot weather, when hiding anything bigger was difficult. I never felt really under gunned, and my Walther was 100% reliable.
However, when I handled a Kahr K9 stainless, I traded the Walther in a minute. The K9 is about the same size, holds the same number of rounds, is a 9mm instead of a .380, and has a much better trigger action and sights.
I've never regreted the trade.