I'm a little biased, and perhaps a little more capable than some. Don has a decent product, but to be honest, the biggest improvement is a result of the right ignition curve.
Even if you have set up your distributor correctly there is still one problem. The advance plate tends to float leading to inconsistancy. The only way to cure this problem is to weld the plate solid. I do not have the capabilities to do so but Don does it. Even if I don't go with his system I will have him do my distributor.
