Aluminum bike durability

I have a 20 year old Aluminum Frame TT bike and a 10 year old Carbon Frame TT bike.  I race on the Carbon Frame bike because it is newer, a better fit, and has more race accessories.  I didn't see any over night speed gains when I went from the aluminum frame to the carbon frame, but the carbon frame is lighter and so going up hills you have slightly less to push which should make you a little faster.  Take every advantage you can from the equipment.  A little bit of time saving here and a little bit of time saming there adds up.  If you can cut 10 minutes off your HIM bike leg that is huge.  Running 13.1 miles 10 minute faster or swimming 1.2 miles 10 minutes faster may seem impossible, but with with optimising all of your bike equipments and a lot of hard work that is more doable.