Adventure bike? I wouldn't put hydraulics on a adventure bike... Getting a hose busted in the wild is a sure way to end a tour ahead of time as hydraulic hoses and bleed kits are much more difficult to source locally than cable/housing sets which you can find in every lbs or even larger super market.
Of course it really depends on how you plan on using the bike. If you don't actually tour, I'd recommend fully hydraulic. The feel in current generation shimano brakes is crazy good.