One consideration is the Ford and Chevy front cab ceiling is significantly lower than a Sprinter, making access to the cab-over bed in a class C much easier, along with more bunk headroom.
Like TXGearhead, I am not a fan of slide-outs. Slide-outs have come a long way since their conception, but I worry how well they work and how well they seal on an old aged rig. If buying new and trading in after 10 years, I think concerns about slide outs is nil. But woe to the person buying that 10 year old rig and own it for many years there-after.
There is also the issue of the extra 400 to 600 pounds each slide-out adds, reducing that much weight-allowance for people, water, gear, food, etc. The biggest class Cs with triple slide-outs can carry the least. You'll be driving your rig alone with your family in the car following behind you.