I have a friend who has an old mountain bike she wanted to use. I did some work on it - adjusted the derailers, tuned the brakes, trued the wheels etc - and managed to turn it from an unsafe mess to at least something that is rideable without fearing for your life all the time. However, the brakes are still far from ideal. They're cheap cantilevers, and even after I set them so the pads are a hair's width from the rims they still don't have enough braking power to be called safe. I suggested replacing them, but the friend in question doesn't have much cash available, so she said the cantis would have to do.
However, DealExtreme just put these Promax V-brakes on sale. At about €10, I should be able to convince her to buy them. Question is, would it be a worthwhile upgrade? I've had the displeasure to work with Promax disc brakes and they were junk, but then V-brakes are considerably less complicated, and even cheap V-brakes should be better than cheap cantis.
Your opinion? Do keep in mind that I'm looking for extremely low prices here.