Shag,
I've got an Axiom setup as well as a Def Tech setup, so I'll do my best to help shed a little light.
I think ultimately it will depend on your friends listening preferences. If he's strictly home theater, he isn't going to go wrong either way, in my opinion. However, if he listens to a lot of music, the Axioms would be his best bet. They're very revealing speakers, or better put, accurate.
Def Techs are warmer, a bit more laid back. They rule for home theater, but depending on a persons taste in music, they may or may not fit the bill.
If you have any specific questions, feel free to ask them and I'll do my best to answer them.