I enjoy seeing the pleasure my gets when I wear one, either vibrating or not. Like Teaser is saying, the Cowgirl position works great for the wife, she can grind her way to orgasm pretty quick. Plus she loves a vibrating penis.
For non-vibrating rings she enjoys the added girth and texture that the restriction of the ring creates. Having been using them for over 20 years, I can say that this type of toy gets used more than any other.