Gary Klein, if you read some about the bikes and construction, really tried to use Aluminum to great benefit...he took the material a lot farther than simply welding tubes together. He called it "gradient aluminum"...the tubes were tapered in both diameter and thickness to put material in the most advantageous location possible. My aluminum Klein is still very stiff but I can tell you 100% that the ride is far and away better from a harshness standpoint than my CAAD9 was. In terms of ride comfort I'd put the aluminum Klein squarely between something like a CAAD9 and a well designed butted steel frame.

Then you throw in the visual beauty of his finishing, the debossed paint, the welds...the frames really are a work of art, much like many of our steel frames, just in a different material.

The Al one just for fun :