Way back in the 70's, the Teledyne Titan while admittedly a flexible frame, was praised by many as a great climbing bike and not for its light weight. It was by others' testimonials and much later when I owned one that if I pedaled at the correct cadence the frame would "springback" at the right time and feel as it was assisting in the climb.
I do not think it would win a race, but it was nice to get something for "nothing". Cycle computers while around at the time were too pricey to delineate the correct rpm, it was done by feel.
Some of this diameter & gauge preference probably is due to riding style as much as anything else.
John Jorgensen
Torrance Ca USA