As an example, a stick through the spokes is very powerful but has lousy modulation. Conventional cable brakes have much better modulation, but the Magura has even better modulation. The stick through the spokes example points out also that a brake can have too much power. When you go over a bump you may accidentally pull a tad harder on the brake lever. Too much power is when going over a modest bump causes you to accidentally apply the brakes too hard.
Predictability is sort of like reliability.
What I mean is that the brake doesn't change over time. All rim brakes suffer when the rim is wet, but some suffer more than others. Again, stiffness helps a lot. It is possible to bleed the system, however it is a little messy. I'm worried that the pipes might get caught somewhere, get a nick in them, get bent too sharply or something equally nasty.