I really like the name Aasimar.  Its a good name.
It just really doesn't say "half-divine" to me.  If you said that name to me and asked me to figure out what kind of race i'd associate with it i'd probably pick our some half-effreet or maybe a cat person or something.   It took me a long time to accept it as meaning "decended from divine", and about 5 seconds to forget i'd accepted it.  Deva works, it makes the right connections in my brain.  Its not half as cool of a word as Aasimar, but its a better word for the job.