I have a pair of the Dia-Compes that Rivendell sells matched to the non-aero Dia-Compe levers Riv also sells (the ones with a quick-release built into the levers). That set-up with the stock pads was not adequate, and scared the poop out of me at my first encounter with a bottom-of-the-hill stop sign. Switiching the Kool Stop pads made a huge difference, The set-up is now acceptable - not great, but acceptable. It still is not as confidence-inducing as my Shimano dual-pivots with aero levers. (The levers may be the difference at this point, but I have not had a chance to put that theory to the test.)
I'd say with any old-design brake on a rider (as opposed to a show-only bike) anywhere with hills hight that freeway overpasses, you gotta get some Kool Stops or Matthausers. Anbd if you put 'em on Dia Compes, be prepared for sqealing brakes for a while . . . . (Of course, if you ever used old Mafacs, you're already used to that.
)