I can't speak for the 20" size, but I had stock SRA's (17") on my 2011. This past winter they had tread left, but I find GoodYear tires harden up more every passing year making them slicker even on wet roads, nevermind snow. Nearly any tire with a reasonable tread depth and perhaps some siping ability will prove worthy if driven appropriately for the weather conditions. I put on Michelin MS2 tires last fall and it is a HUGE difference in winter traction, even more so as this Ram doesn't have the rear LSD.
Keep in mind, if you were to replace the OEM tires with the same tires, the tires may either feel better, or worse, as manufacturers often make deals with say, GoodYear, to provide a tire with a variation in tread compound(s) or chemical composition to make it perform better, or worse, than if you purchased the same tire at another tire dealer. Again, the differences are minimal, but more often than not, OEM's can even 'order' tires with lower tread depth/wear as well. It's all in their marketing plan to keep you going back to the dealer.