RE: Range Finder or Binoculars ?
If I hunted out of lock ons.....I'd sayt the binos were the better option. You can always range your lock on sets by stepping off yardages. If you hunt climbers, predominantly, you should think about a range finder. Things look a lot differently when you're 20' up....and you don't want to be stepping off yardages at each set.
Good luck.