Unless you're doing it in your sleep, you have probably made a concious decision to do so. If that's the case, then there's nothing wrong with it.

It's what YOU want, it's what the CLIENT wants.

I've heard plenty of music that has the vocalist's breathing left in the track, and it can work in the song's favor or completely ruin it. As the other response said, it is pretty much subjective. When I am recording vocals, I just tend to turn to the left or right to take breathes, and coupled with a hypercardioid condenser for vocals, those breathes don't appear on tape, but I just prefer my music not to have them.

I agree with the above - it depends on what sort of music you're making and what the breathing sounds like. Some styles are more welcoming of gentle breathing sounds, but if the vocals are more like "And then I'll *GASP* never see you again *GASP*" then it may be best to get rid of them (or at least severely lower their volume).

Listen to a vocal recording before and after "removing the breaths", preferably with music behind it. Which sounds better? Use that one.