I have just bought the swb 85. so far it seems like a great van, too early to tell what the running costs are though.
One of the reasons I got it was its an ex BT van so was fully kitted and racked out, (I took most of the racks out but some are very useful)
Also it came with a steel safe in the cab plus a night heater and hot water heater, (only for hand washing)
The night heater will be fantastic this winter if its anything like last year.
I have a 650L tank in but you would not know when driving.