I'm thinkin', and I have a 3500, that you have the weight distributed over a wider area....4 tires instead of 2.....and this would make the dually less capable in the snow. My house is on a well and I have a water-softner/filter and need to keep salt on hand to add to the softener. This salt comes in heavy plastic bags in 50 & 80lb sizes. I use 10 bags in the back of my dually and it's like there isn't anything back there...especially the 50 lb bags. To make things worse...well maybe not that bad.....is the fact that there is no locking diff. in the front this would help a bunch. Also, the tires on mine ain't that great in mud and snow (Wrangler AT/S). My $.02 worth.
JP
JP