I don't know about how good the "footprint" is but I have had times on the river when a fly dressed like the one in your photo caught but one tied using the exact same materials in parachute style didn't. Probably only 1/16" in difference in the way it sits on the water made the fish reject the fly. I could see them come to the parachute and inspect it. They wouldn't take it. Change back to the thorax and caught the same fish.
Cheers,
A.