We have a Lance 650 on our Ram 3500 4×4 crew cab diesel and find it a good… no… a great(!) fit. If we had to grouse about anything, we’d ask for a 2nd battery but with our Zamp 160 portable panel we have yet to run out of power. We also had seriously considered the Livin Lite 6.8 but the one thing that really decided things for us was the availability of dealers/service. There are simply a lot more Lance service centers in the West than there are for the CampLite brand.
As an aside, whether you go with the LivinLite or the Lance, with the Ram 3500 you will really enjoy the power to weight ratio! What hill!?