At this writing I have three Colnagos, two Supers from the early/mid 70s, and one Superissimo from about 1982. All three handle beautifully, and are very nicely finished off in all respects (the early 70s frames have finely thinned lugs, and excellent paint/graphics work).
By contrast, in the late 70s I saw a number of Colnago frames that looked terrible: rough finish work, orange-peel paint, crooked graphics. A mess.
I recall one very early 70s Super in my LBS of the time, with all the pantographed goodies, that was a jewel of a thing, flawless in every respect, and easily as well-made (far as I could see), as the finest italian steeds.
My Colnagos are my best-riding frames. Something about them--must just be good design, and a certain amount of liveliness, the result of calculated flexiness. If I had to give up all my bikes, those would be the last to go. But in general Colnagos vary widely in quality; worth looking over any prospective purchase carefully.
The early 70s Colnagos aren't nearly as upright as frames from a decade later, and this results in a more stable, comfortable ride, imho. But they aren't as slack as a 60s italian racing frame (to say nothing of french or british frames of that period), so they're a bit quicker, in acceleration and cornering--a carefully thought-out compromise road frame, it seems, and very likable.
Charles Andrews
When the guy asked what he sold to the racers, he motioned to a Campy NR-equipped Colnago Super and said "Crap like this." That was in the era you mention. Though Colnago has made some great bikes before and after that era, the indifferent quality of many Supers at that time has caused me to alway think of Colnago as a step below Derosa, Masi and Cinelli in terms of quality.
Regards,