I've got a pair of clipless shoes coming in the mail. I do see the potential in them, and in my opinion it forces you to fit yourself to the bike better since you'll be pinned in that position the whole ride.
However, one thing that may hold me back from wearing them the first time is the potential for loss of finesse in near crash saves. Even yesterday, I was braking and slowing in a turn when I hit some wet, slick asphalt. The back end slid around fast. I reacted with my legs to balance me and to prop me up to keep me from going down hard. Truth is, I was using way too much rear brake.
Once I go clipless, I'll just need to be more careful - mindful of what's happening around me. I need to do that anyway!
Cheers!