Regarding full suspension – do you ever see yourself riding without your sons? If you enjoy riding enough to go alone, a full suspension may be worth the extra money, and the new Stumpjumper looks pretty sweet.
If biking is only a way to spend time with your kids and you will probably stop when they move out of the house, then you should be fine on a hardtail like the Fuse.
Specialized is putting out some killer bikes right now, so you should be happy with either bike.