8 inch hydro front and rear is where it's at

I'm biased because I use my bike for DH but hydro brakes put more power into the caliper for force pressed on the brake lever due to the principals of a piston. This means, it takes less force at the lever to get the same force on the brake. This is a hug advantage in DH as it reduces hand pump (yeah I;m weak I would die at Whistler with it's 30min DH's)

I feel there is more modualtion with a hydro set up than a mechanical setup. The lever feel is way more consistant too. When you are on a DH you want to know exactly what the lever should feel like, varations can lelad to accidents.

I don;t buy into this hydros are less reliable argument, I have ridden hydro's for 5 years. Only had to rebleed them a handful of times. However if I took into account cable stretch it would be pretty equal.

What cables have running for them is they are cheaper if there is an accident invovling broken levers (I have only snapped a lever body once) and if there is a problem with the line (hydro hose or cable) a cable is more readily fixed than a hose.

My arguments are probably more relevant to DH riding but some may come accross to XC. I will say now that my old XC bike/beater ride to store bike has cable discs.