My biggest perk of being Silver was having someone thank me for being a Medallion member. (They never said silver as far as I can remember, and I asked my other half who says he doesn't remember hearing them say that, either.)
BUT if I'd flown more and been willing to take more booking chances, I could tell you more about upgrades or lack thereof. And I get luggage fees paid through my Delta AmEx, but still - I think it's kinda cool.