Having partaken in a few one off occasional duos,I found it very restricting, in that I was always aware of doing the song exactly as practised i.e no improvising or free expression. I always felt and still do, that I could perform much better and give more to a solo performance. I don't think that makes me any better than a duo, I'm sure duos have their own methods and practise as well as I do. I just think to say you are better simply because there are more people/instruments/voices in your particular combo is plain ignorant and frankly deluded!