i would say rangefinder hands down! we are talking bow hunting here, so i would say its more important to know the range of the deer thats maybe.. lets say 50 yards max? than being able to see what a buck will roughly score at 200 yards.
your not going to be shooting that far so you should be able to see how big of a deer you're shooting with a bow without the use of bino's.
i dont even use bino's personally.