I agree with Alastair on this. I think the style of music has a lot to do with whether of not I would use backing tracks. I've been successfully gigging for years playing instrumental guitar along with my BIAB backing tracks. Especially in situations where "background music" is required, I can create a nice small band sound without being too loud. However, if i was to gig with my acoustic guitar and voice (finger picking folk, blues, country, etc.). I probably would not use tracks. My own style of singing is pretty laid back, and I don't want to be tied to a specific beat throughout a whole song.

But, I've also heard singers sound great using backing tracks.
"Different strokes for different folks".