A very interesting piece of trivia is that one meter of hydraulic hose WITH oil weighs 5g, while the same length of brake housing and cable is 70g.

2012 Cervelo P5 Triathlon Bike Final Unveil – Speed Simplified - Bike Rumor

Bike mechanics of the world be on alert! Weight Weenies across the Interbutt have been made aware of only benefit having hydraulic road brakes can offer them and you will now be expected, forevermore, to know how to bleed one of the most finicky hydraulic brake systems on Earth. Quit now or forever hold your peace.

Edit: before anyone gives me shit about it I do want to make it clear that I do in fact prefer hydraulics over mechanicals… but only when we’re talking about top-flight hydraulics. I really love my Formula R1’s… but I’d rather be riding Avid BB7’s over Elixirs of any variety. The simple fact of the matter is that the theoretical best-possible-performance you can get out a hydraulic brake is much more difficult to achieve than the theoretical best-possible-performance of a mechanical brake.