I have not driven a C/Pvc MH, but drove a lot of vans with the same cabs over many years, and also 7.5t trucks.
I find our 'A' Class N&B Arto is excellent for driving for the following reasons -
The visibility is excellent(not appreciated on dealers' forecourt or showroom)
Seats are very adjustable.
Wing mirrors, incl parabolic, can be positioned for better view. Downward kerbside mirror can give view all along body.
The side windows are usually double-glazed
Windscreen allows one to see more of the scenery.
The seats have two proper armrests(think some C/PVC use door rest - not adjustable)
There is extra shelf space at the side of the seats for parking mobiles, glasses, bits and bobs.
On ours the driving postion is higher than a van so one has a view over cars allowing one to better anticipate traffic conditions ahead.
When 'White van man' sees you coming he is more likely to give way, in my experience.
From the living point of view I think 'A' Class has the following advantages -
There is an added feeling of space and the forward view from the lounge area is wider and higher.
The additional shelf space as above can be reached from the Captains' seats when reversed.
There is more space to manoeuvre those seats.
They usually come with a drop-down blind for privacy/sunshield and ours can be part dropped and locked.
I suggest you test drive an 'A' Class with these points in mind, and ask to park in an open country area so you can go back and sit to see the difference from the hab area.
If you are still not convinced, then stick with the 'C' Class.
Geoff