Keep in mind that you're not buying high tensile or chromoly steel or even aluminum for that matter. What you're buying is a bicycle frame. Once the frame designer makes a decision regarding the material to be used, that choice leads to other options which all affect the performance and ride qualities of the bike.

Using higher strength materials allows the frame maker to use thinner walled tubes that are drawn with even thinner wall thicknesses in the center than at the ends. The weight benefit compounds itself. First of all, higher strength steel allows less to be used to achieve the same strength. Then, the butted tubes reduce the weight more. Finally, since the thinner center tube sections absorbe more of the riding forces, the ends can be actually be made even thinner than what would be necessary otherwise.

Then, besides weight reduction, there is another benefit. What you would like is a bicycle that is very stabile at the joints, but still has some vertical compliance to give you a smoother ride. High strength steel butted tubes are what I believe gives that indesrcribable steel ride quality that riders like to talk about.