Hydraulic pads are self adjusting, so while tricker to setup, require less ongoing attention as a result of pad wear. Mechanical BB7s are easy to setup, but pad adjustment is manual, therefore requires attention far more often. However, were talking seconds here. I do it once in a while if I notice stopping power is reduced, or as and when I clean the bike. With the BB7s, it is as simple as turning a dial. If you add barrel adjusters, it can be done from a seated position on your bike. I have no messy fluids to worry about. Mechanical works for me, the only reason I haven't tried hydraulic is they are more expensive, and don't see a good reason to upgrade. If they came on a new bike, I wouldn't sweat it, and would just learn to maintain them.