They will get hotter quicker because alumnium is an awesome conductor of heat which is why the make pots and pants out of it.
They make "pants" out of aluminum? Doesn't seem comfortable.
I've noticed that aluminum and most metal after market pipes seem to dent pretty easily. Like lets say you accidently kick it while throwing your leg over.
The carbon ones don't dent.
On the flip side, the metal pipes will hold up to *moderate* impacts a bit better (e.g. getting scraped and mangled), where as the carbon ones usually don't (e.g. crack and fall apart). YMMV