Not having held any of those I can't speak to comparisons, but I will tell you that the crop of newer "easily concealable" pistols is crap IMO. The grips are way too small if you don't use the extended magazines, and that defeats the purpose of the cut down grip. But many people freak out over "printing" and take hack saws to Glock 19s and such. It's just stupid beyond belief.
My back-up is a Kahr K40 and I can put my entire hand on the grip. Don't know how a K9 compares, but I think they are similar. I don't have HUGE hands, though, so YMMV.
Your best bet is to go into a store with a large selection, like Guns Galore in Fenton, and try them all out.