I have owned both an A and currently a C. A Class A is more open and is ideal for full timing or extended long stays. But as Tom55555 said a Class C has some advantages for the casual/part time RV user. Especially when buying an older RV. In my opinion owning a Class C is much lower cost from the purchase price to maintenance.
1.If you are driving east in the morning or west in late afternoon you will appreciate the overhang keeping the sun out of your eyes
2. Class C tires. Available anywhere tires are sold. My last set were Goodyear @ $105 per tire. Class A tires can be several hundred per tire depending on the size and less availability.
3. Any mechanic can work on a Class C because it is just a standard Ford/Chevy van. Whether they choose to or do not have a high lift still limits who will repair it.
4. Drivetrain and suspension. Most parts are on the shelf at any small town auto parts store. No worries about being stranded waiting on special parts to arrive. Many parts are way cheaper also.
5. Cab. Being a standard van cab parts are also readily available. From the front grill to the dash parts and switches. Many Class A parts, even switches are specialized and hard to find. Some people think the steel cab is also safer in a collision.
6. Shorter Class C's are more common than short Class A's. A shorter vehicle under 26 feet can go anywhere a pickup truck can go. Restaurant parking lots, narrow city streets, convenience/gas stores are not a problem.