I owned 2 class Cs, and now a class A. I'll never go back to a C (never say never, right?
). Why? A number of reasons.
On the road: My A is much more comfortable to drive than either of my Cs; you are wedged into an area with a low ceiling and tight legroom in the C, not so with the A. And while the C's cab is narrow, you must always remember that the rest of the rig behind you is significantly wider. Visibility in the A is amazing. Safety? Debatable since you are sitting so much higher in the A that you are likely above any vehicle you might crash into. Towing capacity is typically higher in an A as well.
Camped: The entire cab area of the A IS part of the living space once parked, not to mention the great view out of the massive windshield (both while driving and camped). The larger living area (vs the same length C) is also typically taller and sometimes wider. The inside of my 30' class A "feels" like it's double the size of my 27' C. Significantly larger tanks (fuel, LPG, water, black, grey) means significantly longer periods between emptying/filling. No comparison in storage, either.
Maintenance: There are plenty of large truck shops that will indeed work on an A, and in fact many normal dealers won't work on C's either. So in this category, I default to DIY maintenance/repairs. My C's were a royal PITA to work on. Opening the hood exposed only the very front top of the engine. Removing the doghouse inside exposed only the rear half of the engine, and it's still wedged between the two seats. The middle of the engine was nearly unreachable; spark plugs were difficult to see, much less get to. On the other hand, my class A sits high enough for me to actually sit underneath for oil changes, etc, and the entire sides of the engine and spark plugs/coils are easily accessible from the large wheelwells. Removing the doghouse cover inside exposes the entire top of the engine, from nearly the radiator all the way back the the trans. The larger chassis also means that everything else under there is not as cramped as it is on the smaller, narrower, C chassis.
I spent 25 years in Cs, and they worked very well for us. I've now been in the A for 3 years; I only wish we had made the jump sooner. Of course, YMMV.