Scott,
In the 50's everyone including the Italians considered Reynolds tubing to be the best. By the late 60's I'm pretty sure that opinion was at least even. The late Masi Specials are all Columbus tubing. The first few years (late 69 to about 1971) Masi GC's were built with a Reynolds 531 main triangle and Culumbus forks and stays. By 1972 Italian built GC's were either all Columbus or all Reynolds and they run about 50/50 on which from all of the 1927 and early 1973 Italian made GC's. All of the Carlsbad Masis were full 531 EXCEPT anything built to special order like a track frame or a bike for someone "special" in which case they (Mario) used Columbus tubing.
My 1962 Masi Special is 531 main tubes and either Columbus or Faulk tubing in the forks and stays; I think it's Faulk. I also have here right now about a 1965 Masi Special which is completely built from Faulk tubing. There are several variations in Masi; I have also seen exactly these variations in Cinellis of these same periods. The oldest Colnago that I've seen (the one I have now) is 1970 and is obviously completely Columbus. Colnagos have always been Columbus so far as I know.
That should keep everyone guessing for a while. My feeling is that early on Reynolds was the "nazz", but sometime in the early 60's the tide began to change. By the time I began to build frames in the early 70's both were considered excellent but Columbus had some "mystique" that Reynolds did not have amongst us West Coasters here in the south. Now my feeling is both are great but if I were to have to make a choice for the "best overall frame tubing of all time" I'd go with Reynolds 531.
Brian Baylis La Mesa, CA Speaking of Columbus tubing, I just rescued a bunch of it today! This stuff might have made it's way to the scrapyard had I not taken the day off to save it. A little TLC and some preserative and this stuff will be bike frames some day.