Originally Posted by London commuter

The 700c equiv might even be slightly less considering the braking actually happens maybe 5mm out from the centre of the rotor.

As an estimate, I'd say the drops with 2nd gen ergos give about 180% of the mechanical advantage lever-to-caliper of the tops. 3rd gen the difference is less because the pivots are higher (better design IMO)

To add an empirical datapoint to the endo debate, a few years ago I was cycling on my racing bike downhill on a country road in Wales, going pretty fast (24mph perhaps) when a van comes round the corner at a stupid speed (40mph maybe). I slam brakes and somehow get down the side. Brakes are Campy Record dual pivots from about 2002, bike is light.

Now, the rear wheel lifted a lot but I didn't go over. I'd say maybe 40cm. But before this point of it lifting I could tell it was off the ground and had started to lessen the braking. I then continued to brake with the wheel at a constant height. The modulation was there to do this...