I too have owned both a C and an A and I found the type wasn't nearly as important as the setup and amenities.
Our class C was a 1979 Fleetwood Jamboree (24'?) with an over-cab queen bed and 2 bunk beds, perfect for travelling with our then-small children. And DH and I were younger and climbing up and down to/from the bed wasn't a problem. Neither was pulling the steps out and in.
Our class A was a 1992 Fleetwood Flair (diesel) (34'). Rear queen bed, convertible dinette and sofa, real closet, microwave. Great for us, no climbing, and if a (now grown) kid wanted to come along, they could deal with making/unmaking a bed.
We are in the process of buying a motorhome, and my physical limitations have made shopping even more ... interesting. ;) We happened to find the combination of features I required in a Class A, but I would have gone for a Class C if it had had the right features. An A is simply what was available locally at a price we could afford.