I like the 3" and less crowd. Heck, I even cut a few N frames down for myself.
The 3" K frame seems to balance really well for me, and I like the full length ejector rod.
I like my 2-1/2" Model 66, but I LOVE my 3" Model 66. That full-length guide rod is just the perfect balance between functionality of a shorter barrel revolver, aesthetics, and feel in the hand.