My personal taste is for unaccompanied singing, and that's how I prefer to perform. I find it gives me a better chance to 'find the zone' or whatever phrase one likes to use for that zen-like state where singer and song are extensions one of another.
The other problem is that I play the diatonic box, and the mechanics aren't conducive to singing (although I know Pete Coe, Tony Hall and a few others can sing and play well, I'm not that accomplished!).
And, for listening, I do prefer unaccompanied singing; be it sean nos, English solo style or a capella harmonising. The Voice Squad and CB&S are superb at this, and an instrument would destroy the magic, I feel.