It was much simpler and made a much more direct connection with the derailleurs without all the extra curves of cable and housing (heck, FD didn't even need housing).
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Bikes: 1996 Eddy Merckx Titanium EX, 1989/90 Colnago Super(issimo?) Piu(?), 1990 Concorde Aquila(hit by car while riding), others in build queue "when I get the time"