What I found annoying is that aluminum cans can only be used for water and lava. I wanted to use my liquid transposer to put oil in aluminium cans but nope that only works with tin cans. (Speaking of which, all my tin cans seem to have vanished from my transposer-enderchest-transposer oil transport system. They must have escaped from the BC pipes and despawned at some point.)
Anyhow, since I don't have GT, aluminum is currently useless for me, and will be until I want lava or water cans.
They're even less useful than that... I made some aluminum cans when I first started (before I had a lot tin), and they refused to pick up lava from the environment like regular cans are able to.