We moved from a TT to a Class C, so here are a few points from my perspective:
You will have limited visibility in a C. Watch how you pull to an intersection at a light...the overhang can block the light. When making turns at an intersection where you have to stop and look, stay back enough to SEE on the your left (as if turning right onto another street). Maybe the same with an A on that one.
We looked at both and indeed we liked the more usable floor space in an A -- driver/pass chairs can usually be swiveled to use as seating. In a C, not so much. In fact, in a C, the driver area is lower than the floor of the living space.
So why did we go with a C? Large overhead bunk (the overhang) is great for storage and sleeping. Price point much lower (we bought new). For a simiar A, we would have a gasser and most likely would be same Ford V10. We do have hydraulic leveling...we added it after. As far as getting up to move about, we don't do it regardless. Can be dangerous and we usually plan a trip with a rest stop every hour or 2 since we bring dogs with us.
Our C has a ton of storage ... I mean it has a huge cavernous basement, with lots of smaller storage areas around...so no big advantage to the A. Bottom line: we found the C (for us) had better pricing, had decent layouts to choose from, had a generator and leveling jacks were optional, and simply put -- fit our needs.
The thing to remember is an RV can be about compromise ... give up something to get another. Occasionally you find an RV (A, C, B, TT, etc) that fits your needs perfecting you don't feel like it's a compromise. That, to me, is ideal. For us, a TT was perfect...we could pay cash and I had no "extra" drivetrain to care for (engine in the motorhome). But, we could also not stop and see things on our journey..."worlds largest ball of twine" and other such things...because we could not run our AC while parked in a TT. The C for us fit our needs.
Lastly, length as you mention is important. Ours is 33 feet long. We can fit just about, but not all, places we want to go. Longer and yes, it can be an issue.