Both. Toeclips, straps and usually real slotted cleats on my fix gears and LOOK Delta compatibles (Forte) on my geared bikes. I am starting to go with Shimano XTs on both as I have acquired winter boots that are only MTB cleat capable. So far I like them and walkable shoes with cleats that I don't have to pay a cobbler $80 to modify is a real plus!

My two big concerns that drive pedals are 1) I need pedals that will locate my feet properly to keep my knees happy. That means real toe-in in addition to what my feet take naturally. I use the LOOK black no-float cleats and old fashioned slotted cleats do this just as well. And 2) my feet better never detach from the fix gear pedals when I am going downhill! EVER. Slotted cleats and quality leather straps make for real peace of mind. I am beginning to have confidence that the XTs with the release set dead-hard are OK but the jury is still out.

Ben