Aluminum = stiffest, lightest. Usually not real compliant. Can be made to feel responsive. Rear triangles on newer Cannondales are rather remarkably compliant/responsive for an aluminum bike. But noticably stiffer than Ti nonetheless. BIG improvement over what they had 7+ years ago. I know, I have a 1998 Cannondale CAD 3 that I ride as a rain bike.

Steel = great ride, compliance, ride, heaviest

CF = great road shock absorption, BB stiffness, very light, can be a bit numb feeling

Ti = lighter than steel, 'zingier' than steel, can be made very light too. Ti frames tend to weigh 2.5-3.5 lbs. without fork, a few (like the Litespeed Ghisallo) as light as 2lbs. or less (but that gets VERY pricey indeed).

My Ibis Ti road weighs 3.2 lbs without fork. Pretty average weight for a 3.2/2.5 butted Ti road frame these days. In its day (1995) that was very light. Still builds up into a relatively light road bike (mine weighs 17.5 or so, a few light parts and it would be sub 17. That's real world weight - not 'my bathroom scale' weight often offered on this brain trust.