I really don't mind people bringing their blue books (RUS) to song circle, I just refrain from going to those sessions myself. But I'm perfectly tolerant.

When I'm playing backup guitar or fiddle and I don't know the music that well, I don't mind using the notes on a music stand since I'm not the focus of the music - the singer or lead player is the one of interest and probably shouldn't be using written music. Besides I may be called at the last minute to back up something I'm not familiar with, so I don't have time to learn the new music.

Cheers, S. in Seattle