Originally Posted by John E
Returning to your title question regarding old bikes' traits, what I value most about classic road bikes is appearance; relaxed, comfortable frame geometry; generous tire clearances; and incredibly durable, easily maintained friction gear changers. What I like least about them are ineffective brakes (primarily due to brake pads and cable housings, but the long reaches and nonaero brake handles both reduce leverage) and OEM low-pressure clincher tires.
I think brake cables and housings are an area where vintage, with two very notable exceptions, is not better. I've made huge improvements in some old brake systems by rebuilding everything with either new cables, with vintage Nuovo Record housings and inners, or with Modolo housings and inners. Paying rabid attention to dressing the ends and proper routing helps get good performance out of old brakes. A lot of the cables of yesterday were garbage. The NOS DuraAce set that came with a set of 1974 DA calipers ended up being as squishy as can be, same for several sets of Shimano 600 6207 series.
Keep the old calipers and perhaps even the shoes. I haven't found modern shoes to be much better than old Campy and Shimano once the entire system is clean and lubed and the cables are properly set up.
Use single pivots, it puts hair on your chest!
Road Fan