The problem seems to be you find the performance of the brakes somewhat lacking. I just checked the Dahon site (after looking on Amazon) and I didn't see what type of brakes are being used. That might be the problem right there- not all rim brakes are as effective as others.

I've had to use my son's BMX bike when my bike was in the shop before. First time I went down a pretty steep hill and hit the brakes to slow down... I survived, but it wasn't pretty.