Man, I taught in a school that had hard wood - it is preferable to the nasty short napped carpet I currently reside in, for sure. So, go for the single flex; they are awesome in summer sock less as well.
This is true. And, Rob, I'm a teacher too. I had the Alden Snuff Suede PT Flex boot from LS and I slid all the time on those shitty commercial tiles in public school buildings. I'm hoping my Leffot cap toes aren't the same. The single sole gives you the most visceral "ground feel" of all the soles on any shoe I own, save my Vibram Five Fingers. Which is good and bad.