We previously owned a Motorhome, a Peugeot Boxer based unit, so front wheel drive (FWD).
Me and the wife loved the facilities and moderate size (Just 6 meters long), but it weighed about 3 ton when packed. This lifted the weight off the front end and reduced the front wheels grip. It would get bogged down really easily. At festivals or when going to remote fishing spots, getting stuck was a frequent occurrence. This spoilt it for me, as I was always anxious when pulling on to grass, even fairly flat stuff, that I wouldn't get off again.
I decided to go the Campervan route, this allowed me to design a layout which suited our specific needs and possibly develop a light weight build. I considered Rear Wheel Drive (RWD) fitted with a Limited slip differential, to help in the rough and mud. I wasn't sure how much better the traction would be with this set up though. After much deliberation, I chose to go all out and get an All Wheel Drive (AWD) van. A quick look at Sprinter prices ruled it out, so that meant it was a one horse race. After a few months searching, I found this specemin about 200 miles from where I live:

I have quite specific ideas as far as layout is concerned. A double bed across the back with garage underneath is ok for couples, but what if I want to go to a festival with a mate or on a fishing trip. Two single beds is more versatile, if harder to accommodate. My initial thoughts are along these lines, with a full height storage space at the back to access the utilities and wiring, plus hoses, leads and ramps.

I'll keep this summary up do date, but if you want more detail, follow the link in my signature, to the project on my blog site and the whole story.