+1 on these aren't flawed technically.
I read the Sheldon Brown blog and something didn't quite add up. Reading his description twice I also realized the initial setup was wrong. Unlike standard shifters, The rear lever must be positioned at the largest cog before installing/trimming the front derailleur cable.
(When the right lever is flipped back, the left lever is cammed rearward, thus shortening the cable. When the right lever is forward and chain is in the smallest cog, the left lever is cammed forward, thus pulling the cable and the FD trims outward.)

I acquired one of these when they were first introduced. Sorry, I no longer have the factory pamphlet with exploded view.
Mine has been working fine on my Nashbar since the early 80s.