Originally Posted by
Kilroy1988
Well, we're talking from two different perspectives here. I agree entirely that "all steel has the same stiffness" if your measurements are identical. However, I am talking from the perspective of a built frame. The stiffness of the frames I've had - and the advertised utility of a frame - made from 853 has in general been greater than my 531 frames. The inherent strength of the frame material allows that to be accomplished.
Please note that in my initial post you quoted I said a "stiffer frame," not "stiffer steel."
-Gregory
I thought that might've been what you meant, I just wanted to be extra clear for
Bad Lag 
Since they asked (as you noted) a well-trodden question and your response had some assumptions about an 853 frame that he may not be aware of, like how oversize tubing affects stiffness.