This short article from the NY Times may help you to decide if you want to get the vaccine.
If you get it at age 60 it decreases your chances of getting shingles by 64% in the next five years.
If you get it at age 70 it decreases your chances of getting shingles by 40% in the next five years.
If you get it at age 80 it decreases your chances of getting shingles by 18% in the next five years.
It is not known if the vaccine is still effective after five years. The literature suggests that those who have had the vaccine seem to get milder cases of shingles.