FWIW, came across this thread. Thought about it, as my commute times, despite my fitness getting better post knee surgery, have leveled out. I climb and descend both ways.

So this morning, on a whim, I decided that instead of my normal riding on the hoods, I'd stay in the drops the whole way. Not easy for me, I do have some back issues, but my bike's bars are relatively high for a road bike (it's really a touring model anyways).

So, in the drops, I took a full minute off my best time (22 something compared to 23 something). My gps only calculates my actual movement.

I certainly felt like I worked harder, although I won't know until I review the data. I am such a nerd.