Jerry said: "Something almost supernatural about the feel of a PX-10. "
I wouldn't go that far but I think that Peugeot did a lot of things right. They were committed to a very light weight, reasonable geometry and good value. I have a 1951 PH-10, the forerunner of a PX-10 and it is a delight to ride. From at least this point on, Peugeots were lively and comfortable, certainly a great bike for long road races and centuries. Peugeots got it right early and didn't change much until pretty late in the game. As to the complaints of whippy, too much fork rake etc. I think these were just design choices within their philosophy and if you didn't like those things versus the other merits, then you didn't buy one.
Most riders who emphatically like PX-10s tend to be lighter weight (or were!), so the Peugeot light weight philosophy is a better fit. I think they also appreciate a bike that feels as good at 100 miles as at 10 in terms of comfort. French parts generally require tolerance as to durability so it helps if you don't mind keeping after the bike. I think that Peugeot had pretty good standards of quality control. Not that the standards were very high, just high enough and very consistent.
I have said before that Peugeots were very easy to assemble and they were one bike where the dealers were sure to make money on the sale.
My overall point is that following WWII and for about thirty years, Peugeot establish a benchmark for value and reasonable performance for a lightweight racing bike. It wasn't that hard to build a better bike for more money, but it sure was hard to build one for less. As to the overall ride, one false move and you had nothing on the Peugeot and many bikes came up short in one way or another.
Joe Bender-Zanoni
Great Notch, NJ