I rode with SPDs on my road bike for 1 season and decided to go back to platforms. Maybe frogs would have been better for me, or some other system, but it was SPDs I tried and they didn't work for me so I decided I wanted to ride free.

For me, clipless is really dangerous. I had one fall that was extremly painful, leaving me with a humongous bruise on my hip and limping for days. Plus I just do not like the idea of being attached to the bike if something were to happen.

I prefer riding free because I want to be able to move my feet around. I want to select my shoes on a whim. I can wear running shoes to ride to the track for a run... or my sandles to ride to the pool for a swim.

When I switched back to platforms, my speed & calorie burn didn't change, so I figure it wasn't worth the risk anyway.