The only time I've ever benefited from having a snubber was when I was putting lots of horses down and was using a stock rear suspension. The power tended to override the springs ability to hold things down and the snubber helped resist that rotation. After switching to the proper SS springs, the snubber because worthless as the springs now created enough body seperation that I never used the snubber.
FWIW, Fox bodied mustangs also use a snubber, but it bolts to the body pan instead of the axle.