All of this is pretty subjective, which is really the point and the fun of these forums so much of the time. Here's my two pennies worth of speculation:

I have owned a '72 P-13, and I still have a 1989 Waterford built Paramount and a 1966 P-12. The '89 feels fast to me, yet is still comfortable to ride over distance. The '66 feels built for distance and long hours in the saddle for some reason. It fits me very well and I've used it and my Boulder as a baseline for size and geometry comparisons. The comment above that "it depends" is really true. I'd have a hard time deciding which of the two to pass along if it ever came to that. For what it's worth, here's a comparison I did of the two bikes (which are essentially the same size) by overlapping them in Photoshop:


The really noticeable differences are in fork rake, trail, and wheel base. If the stems were the same, the reach would be very similar.