the thing is, a
the thing is, a test like that would only test the brake in one direction (IE forwards). Going forwards and having the brake work well (bite) is all well and good for back hopping down slopes, some drop gaps and impressing your friends, but you need a test that allows for backwards power too, like for landing hooks, gaps, taps, sidehops, most natural etc.
This is why the magura/v brake argument happens because some people prefer bite as it gives them confidence whereas some people are willing to sacrifice a bit of bite in order to gain better braking power for when you really need it.
You just can't beat a v brake for sheer holding power, if I was to build up a bike for comps/tgs I would ride a rear vee without question.
As for discs, I was pleasantly surprised by the Magura MT2, it's pretty dam light and comfy yet pretty high on stopping power. I'm not a huge fan of Hope brakes, I've had nearly ten sets now and they all work fine for about 3-4 months, then they just go downhill and I've never found a way to get them working like new again. This has happened nearly ten times!
Saints are VERY good, but quite weighty and don't have a split bar clamp (on the newer ones they do though). They suffer a bit from pad wobble, but the power is definitely up there with the best.