I live in Seattle. If you have ever ridden down a busy street, on a rainy day, with a bus on one side and high curb on the other, the value of disc brakes becomes immediately apparent. And that's just on pavement. Now try the same thing in a steep, muddy chute where if you fall, dying is one potential outcome. Then there is increased rim and tire life, cleaner hands when fixing flats, and the aforementioned still working with a bent rim. To me the only downside is with hydraulics, which are mostly impossible to fix in the field.
In the next 10 or so years, a regular entry level bike will have disc brakes and an internally geared hub. Most shops around here, including the one I work at, have mid to upper level city bikes equipped like this already. The manufacturers will want to simplify their assembly lines and inventory needs, just like with 1 1/8 headsets and 31.8 clamp diameters. This will help keep the final cost to the consumer down. What's funny is that even with bikes being made in China, they aren't cheap enough, so we are now seeing bikes being made in even stranger places, like Vietnam and Cambodia. Not Wal-Mart bikes either. Good brands like Kona. Just look for the sticker, it's there somewhere. Sorry I'm rambling. In summation, disc brakes are worthwhile.
In the next 10 or so years, a regular entry level bike will have disc brakes and an internally geared hub. Most shops around here, including the one I work at, have mid to upper level city bikes equipped like this already. The manufacturers will want to simplify their assembly lines and inventory needs, just like with 1 1/8 headsets and 31.8 clamp diameters. This will help keep the final cost to the consumer down. What's funny is that even with bikes being made in China, they aren't cheap enough, so we are now seeing bikes being made in even stranger places, like Vietnam and Cambodia. Not Wal-Mart bikes either. Good brands like Kona. Just look for the sticker, it's there somewhere. Sorry I'm rambling. In summation, disc brakes are worthwhile.