Because I work a 56 hour shift, and have a wife and three kids at home a "shorter" smoke works best for me. Don't get me wrong, I haven't found a particular vitola that I don't like but a corona, robusto or petit corona really hits the spot. When I have time to relax on the weekends I'll fire up a toro or something of similar size.
Like Dustin, I get a more forward flavor punch from a smaller RG. With larger RG smokes I can pick out more complex flavor profiles and aromas.