Lots of good info here so far! The OCCC is a HUGE consideration that MANY who buy RV's never consider until it is too late. I was one of them. Luckily, it worked out for us given our typical usage.
I thought I would add that as a 24 foot class C owner, when I step into a 30-32 foot RV it feels massive inside! That back queen bed that you can walk around is a game changer. Of course, for our personal purposes, National Parks and State Parks in the West, a larger RV at 30-32 feet as I previously mentioned would not be a good choice for us weekend warrior types as the number of spots available out west are already limited even at 24 feet. But still, after a week long trip in a 24 footer with two adults, two dogs and a kid, I am ready to be home in my California King bed! :)
Just some random thoughts...