I've heard two folk bands (playing traditional dance music) recently. I heard them play, on successive days, on opposite sides of the country. Members of one band played from a score while the other lot played from memory. I found the first band to be a bit dull and mechanical but the second band had real 'soul' (for want of a better word) and their playing was exciting and fun to listen to. The sad thing is that I know members of both bands and also know that they have similar levels of technical competence and ability.

With singers it's a bit different. In my experience, singers who rely on a cribsheet (paper or digital) are far too often crap - and never get any better. On the other hand, singers who sing from memory can (obviously) be crap - but often they improve with time, mainly, I assume, because they're putting the work in.

Finally, let's be brutally honest, I DO NOT want to spend my evenings listening to souless crap!