Not enough info to offer an opinion. What kind of off-roading? Are you talking about just cruising around on dirt roads? Making your own roads? Or are you talking about balls-out rip-it-up off roading? If it's the latter, then neither one is going to hold up without serious modifications. Otherwise, based on my 30+ years of truck ownership and off-road cruising, you cannot beat an F-150. It will haul as much or more weight than a Chevy 2500 and go pretty much anywhere you want to go. I've owned several Fords and Chevys, they're both good vehicles, and have found without exception that the Ford is a superior vehicle over all. The Chevy does ride better, but that's because their suspension isn't as strong (thus explaining why the F-150 will carry more weight that a 2500. This I know for a fact based on experience, I not trying to bash Chevy's. As for faster: my current 2007 F-150 4X4 with the 5.4 will outrun pretty much any 2500 I've put it up against, especially when hauling the 22' travel trailer behind it. I have a buddy with a 2006 2500HD with the 6.0 Vortec motor. We've both pulled the 22' trailer and my F-150 pulls it easier, smoother and faster that the 2500HD.
