We owned a class A for eight years and used the jacks most of the time. Last year we purchased a class C w/o jacks. I have not really missed the jacks as everywhere we have been had fairly level sites. We use drive-on leveling blocks when needed now.
Jacks are nice for helping stop movement when you walk inside, but at $3500 or more, we have adjusted to life w/o them.
The step up you reference is for the wheels and axle. No big issue with us, just be aware of it as you walk through.
I have never seen roll out windows, but I don't see why they would be an issue.
Hope my thoughts have helped.