I think they both sound great, haha...But I always call call her by English translation name, Aeris. It just kinda stuck to me, as, well, I only played the English version of it, not the Japanese version. But yeah...They both sound like good choices to me. If I wanted to, I could probably switch from one name to the other, or just use one continuously...

But yeah, Aerith does have a lot more meaning to it. SquareSoft Japan had made sure it had meaning to it. But since I pronounce Aeris, "I-Riss", and not, "Air-Ees", the name automatically sounds like the name of a flower. I don't know if that's the proper pronounciation or not, and I don't really mind if it is either, it makes sense, in my opinion.

But both sound just fine to me.