If you're refering to Attitudes by Debra then all I have to say is they're expensive, they're revealing, and they were featured in French Novelty, so yeah, it's acceptably cool.
With prom dresses, the brand doesn't really seem to matter as much. The best thing I can suggest is to make sure the dress is pretty and fits with your daughter's sense of style. Not the one that you wish she had, but how she actually dresses. She will like it if she feels comfortable and pretty.
Because there are so many different types of dresses in stores, an Attitudes brand prom dress is acceptable as long as it's in a flattering cut, color and style for your daughter.