A good light makes a great difference.

I have two friends who both play in bands that don't use lights, and in my opinion it just looks wrong. I just can't convince them of how much more professional they would look with a simple light. They just don't see how it will add to their music which is a fair point, but playing in the dark or under normal lightening just look unprofessional.

They don't like the heat they generate either , but you can get full colour LED lights now that solve all that.

Cheers
James