Originally Posted by T-Mar

I don't know where you are getting your data but my charts show Reynolds 501 to be 320g lighter than Aelle for an uncut tubeset, which is significant. Reynolds 501 was also manufactured from a stronger CrMo alloy, while Aelle was CMn. I've always considered Columbus Matrix/Cromor to be the direct competition for Reynolds 501, as it was also seamed, butted CrMo and aimed at mid-range price levels. Aelle was already five years old by the time that Reynolds 501 had it's debut. It was closer to Reynolds 531 Plain gauge. There was butted version of Aelle, called Aelle R.

Butting may or may not be superior, depending on the relative gauges and what the designer is trying to achieve. Typically, it will be lighter and more compliant but it typically won't be a stiff. I could see some builders favouring Aelle on TT bicycles, especially if they are employing bent or aero profiled main tubes. An aero tube will not be as laterally stiff as an equivalent gauge round tube, so using a plain gauge tube with an aero profile was a method to maintain acceptable lateral stiffness.