I've been Silver Medallion on SkyMiles for several years and occasionally have gotten upgraded to Delta Comfort and one time to First Class. But at least 70% of the time, there are no upgrades. I just made Gold Medallion and I'm wondering how much that will increase my odds of getting upgraded on a flight. I know there are possibly more people making that level now if they have the Delta branded AmEx Reserve credit card, as I do, so perhaps it's a moot point and I'll be in the same group as with the people before, just in a shinier level.