Kahrs really are bigger. Kahr pulls the same trick that Glock does, telling you the slide length instead of the overall length. My MK40's actual dimensions are...
5.6" long
4.3" high (including sights and magazine)
1.08" wide across the slide release
0.98" wide across the grips and the slide (same width)
Personally, though, I'm happy with it as a pocket carry gun. Yes, it's heavy. So is a belt gun. After a few days, you get used to it. After a few months, you walk crooked without it.
I am really thinking of saving up for a Seecamp .380, though, as an "always" gun. Backup if I've got another one on me, primary only if I really can't manage to hide anything else.