Some perspective about materials from me (and since it's from me take it for what you paid for it). Here is a list of bikes I've owned and my thoughts on them in order of puchase:

1988 CIOCC Lugged Columbus SL . Great bike, stiff, light for it's time, handled great.

1991 Tomassini Lugged Columbus SLX. One of the best bikes I've ever owned. Fast light for it's time, handled like a dream.

1995 Vitus 979 lugged aluminum. Light and flexed like paper. Went up hill very well but was scary on descents.

1998 Cannondale. Aluminum Stiffest bike I've ever owned. Had for less than a year as it was so stiff that it just about rattled my fillings out. Handled great and climbed better.

1999 Serotta custom lugged Reynolds steel. Very comfortable bike. Didn't do anything spectacularly well but was a great all around all day bike.

2002 Cinelli Starlight. Columbus Starlight Alum tubing. Stiff and fast. One of the best handling best climbing bikes I've owned.

2004 Orbea Orca. CF. I hated this bike, it was stiff but not very compliant, I could never get comfortable on it and the handling was very twitchy.

2004 LOOK 381. Lugged CF. One of the top bikes I've ever owned felt more like a steel bike than a CF bike. Handled well and climbed great. Very comfortable.

2005 LOOK 481. Lugged CF Same as the 381 as far as geometry but the 381 was more comfortable due to less HM Carbon in the frame.

2006 Cannondale CAAD8 Aluminum. Best bike I've owned since the Tomassini. This thing does every thing exceptionally well and it's pretty compliant. I can ride this thing hard all day and get off feeling fine.

Bikes I've spent at least 3 hours on.

Cannondale Six13 as good as the CAAD8 but more compliant (and that's saying something)

Cannondale System6, the Six13 but a tad more compliant and stiffer.

Colnago C-40. Really was underwhelmed with this bike. This may have come from such high expectations.