So I know there are a lot of different kinds of tubing out there, Hi-ten, Cr-Mo, Reynolds...but is there really a huge huge difference between them? Am I really going to notice the difference riding a 1020 Hi-ten frame vs. a Cr-Mo?
Higher quality steel tubing is thinner-walled and butted. It is much lighter and has a livelier feel compared to plain guage hi ten steel. This is especially noticable in the fork.
Between the various typs of quality butted cycle tubing there is less difference.
One problem in comparing is that no-one builds to a high quality using low-end tubesets. In some blind tastings (ie built up into the same design) it is hard to distinguish a good tubeset from a premium tubset.