We’ve had ours for 2 years now, had two longish (3 weeks and a month) trips to the continent, plus loads of travel round the UK, with no unusual problems.
Not much to add to what Simon and Khani say- bongofury membership is the best money you’ll spend- loads of backup on the forum, plenty of tech sheets covering fixes and modifications. I’d recommend either buying a vehicle off the forum and/or co-opting a local member to have a look at the van with you- they’re pretty helpful in that way.
One must do is to fit a coolant alarm to cover the eventuality of sudden loss of coolant- you’re engine’ll be toast before the normal temp gauge responds if this occurs.
Oh, and our mechanic, who specialises in Bongo’s only charges £25 an hour- a refreshing change from the cost of servicing late model cars.