I run SPDs on my commuter (Shimano A520s) and have mountain shoes (walkable) and road shoes (not so walkable) that are set up with SPD cleats. There are road shoes that will take 2 hole cleats (I use Pearl Izumi Vagabond) if you want to go that way. I also like the SPD SLs and run them on my road bike but the SPDs work better for commuting IMHO.