Hydraulic brakes are the cat's pyjamas, really. I expect there have been some improvements since I was using Avid BB5s, but my experience switching to some mediocre hydraulic brakes (Hayes Stroker Trail) then good hydraulic (Shimano SLX) was that hydraulics are far superior. They may be more complicated to maintain and service than cables, but hydraulic systems are less likely to require repair or maintenance (in my experience).