I know that Roger Stern had plans for the character, but from my understanding, Marvel didn't want to use her, and after that I heard that she was depowered and pretty much forgotten about for quite a while. Writers don't seem to really want to use her a lot. I haven't read Nextwave (But I do kind of want to.), but I know that she had a big part in that. It seems that Roger Stern is (Or was.) really the only writer that used her or that really cared for her (Which makes sense, since he created her.). I have read a lot of people say that she's too powerful. I don't think that should be much of a problem, though (Especially given Ms. Marvel.). I guess that people didn't find the character to be all that interesting. What was/is the problem with her, and why didn't they let Stern do what he wanted with her?
Her power makes her nearly unbeatable : invisible, intangible & light speed.
She needs a Kryptonite which would make her more vulnerable and, thus, provide a challenge for her, once in a while. The Masters of Evil once used the Darkforce against her and it was a cool idea.
She doesn't have her own rogues gallery and "a hero is only as good as his villains". Obviously, Moonstone, Blackout and the Living Laser could have been in her rogues gallery.