It's somewhat of a picky vocal mic.
I've never really known it to sound particularly bad on anthing. Although I wouldn't layer a buch of background vocals with it. That's really not it's forte. And it's not a rocker's mic, either. I don't think I'd want to put it in front of a screamer of any sort.
On the right voice, it can really sound like magic. On a clean guitar amp it always sounds like magic.
People who would sound good with one: Think softer, mellower type crooners. Someone who sings mostly airy and breathy stuff. It has a noticeable scoop to it in the midrange that makes it really well-suited to people who sing too midrangy, grainy, or nasal. Great for pop music and especially R&B, because it's a pretty slick, produced-sounding mic -- as most BLUE's tend to be.