Makes total sense, and would be fun to have. But I can have only so many bikes.
About the flat pedals vs. clipless, I like the vids put out by these guys. Technique tips, gear tips, and some good ol' british isles bike nerd humor.
Anyway, here is what they have on flats vs. clipless, or as they say, "clips."
For the kids who go downhill fast.
For most of the rest of us. (EDIT OOPS had the wrong vid in there. Fixed it.)
And dorky roadies. I can't think when I have ever seen roadies on flats. But it is a pretty funny video with some interesting information accumulated scientifically.
They did another vid before this one in a lab, where the flats were surprisingly close in terms of heartrate numbers and the like in the lab.
For me, I am going to use them as a learning tool to evolve my riding away from over-reliance on the clipped in feel for bunny hopping, and bike maneuvering, and for learning better techniques on flow trails. Then likely, for most of my riding, I will end up going back to clipless, but hopefully with improved skills. Not likely I will be riding speeds and terrain such as that first kid was.