Over the years I've raised my handlebars to help with neck pain. Now, probably due to my shoulder-squeeze exercises, neck pain has disappeared, and I'm moving them back down, bit by bit. I figure:

1. I'll be slightly more efficient
2. I'll be taking weight off the saddle
3. The bike won't look so kooky anymore.

For the first time in years, the handlebars are lower than the saddle:



I realize the efficiency gains are small. Are all of those gains due to wind resistance, or is there an advantage to the body positioning?