Originally Posted by Mo'Phat
Hands in the drops are about 4"-6" lower than a true aero position (if your drops are in a racing profile ie: 3" +/- lower than the saddle) and about 4"-6" closer than aero. A close approximation would be to sit on the bike and put your elbows on top of the bars on either side of the stem. You'll probably find that you need to shift your hips forward, which might force you to move your saddle forward as well.
My bars are 2" lower than saddle... and I do notice repositioning my hips / butt when in the drops.
I assume the elbow rests are variable, and keep you off the top of the bars... so my worst case will be in the drops? If this is true, I think I can find a comfortable position with the Brooks.
(road bike that I won't change my position on - just adding the bars for a brevet so it won't be a Tri or TT bike / position)