I've been using a B&W patriot with rails in my 12 2500 CTD. It's been flawless for 4 seasons. I've gotten tired of hoisting the heavy bottom half in and out of my truck and now have an Anderson. It's a little trickier to hitch with but is sooo much lighter. I've only had a chance to use it a few times but so far I like it.
I will add though that you need to keep an eye on your pin weight. 12 2500 CTD trucks have really low payload capacity. With passengers, gear and pin weight you'll be definitely over the trucks GVWR, GCVWR and near the RAWR