See I'd rather use "is" because saying "are" implies that each individual member is awesome, when that may not necessarily be the case, but together, combined with all the other studio people, like producer and mixer, et al, whom result in making their music in recorded form, they result in awesome. Because really that's all that matters, sounds resulting under a particular moniker, to which is being referred.
And your example fails because it would be impossible to say "Bloodbath is a fag" because the fag would have to refer to the sexuality of the members themselves, completely independent of the band, requiring you to use "is" or "are" depending on whether it is the group or an individual.