Originally posted by Mrs. Bupu-chan Maynard

Show me a person who has sat there morphing those damn Unknowns until all stats maxed?
I did. And I did not spend thousands of hours on ff7, it is quite fast once you manage to have a strong enough Yuffie.

And since I prefer not having an uber team during the actual game, which would spoil the fun, I see no problem in having aeris in your party, and using her efficiently. Of course the more you max your team members, the more she'll look weaker in comparison. She was not intended to be a high-level character.
However, as long as you have "normal" levels, she is pretty good, because you are quite often in need for support. And as far as magic users go, I do not see anyone who better fits this role than her.