while I always preferred the hound to the hammerhead, i found that the hammerhead brakes were better; it has adjustable (short or long linear pull) levers from tektro because I needed these for the hound (easier to order 2 sets) and the regular dahon dual pivot caliper which are pretty much the same as the tektro calipers.
when I first built the hound, I fitted some standard side pull dia comp caliper for bmx due to tyre clearance requirement and while they work, they were not are good as the dual pivot.
i fount that dia comp makes a bmx dual pivot caliper (dia comp 806). I fitted one on the rear and it works well with the front v brake (hence tektro adjustable levers).
now the hound brakes very well and i can do skid competition with the kids (makes me feel 30yrs younger)