Steel vs. Alum. No difference in my mind. I am 235 pounds of middle aged thunder. Ride steel road frames that are antiques with well over 23k on them. Also have a Habanero titanium frame that is ridden most of the time now. It has the grace of steel, stiffness of slightly less than alum, and the durability of ti.
You ought to check it out, especially if you have access to parts on the cheap. Never will I purchase a new alum or steel frame again. Hi dididly dee, its ti for me! Totally hooked, no scratches, chipped paint, corrosion or too stiff or flexy a ride. Kind of like a good bowl of porridge.