I took a promotion and pay cut last year. While I didn't really want a paycut the promotion meant that i was no longer a shift worker doing 4 on 4 off, with no social life as all my friends worked Mon to Fri. Now I work Mon to Fri I can have a social life, I just can't afford it!!
I think that generally you just have to look at a bigger picture. Does it give more job security, or job satisfaction? Are there other benefits? Only you can decide what is right for you.