i really notice the head shape being different. The tem has a longer head and the azul is more round and shorter...thats pretty much what i notice. but still pretty hard from fry but as soon as 4" hit you should be able to tell alot easier.
check it out...the azul is mine and the tem is courtesy of bruce! sorry my carmera is nowhere near as good as bruce. both are 2 different varients of azuls on the top photo (notice the difference in appearence but same in head shape)and a tem on the bottom...now for me this is the usually that i see but still can be easily confused.