On of my mates sold his T4 when he found out that it would be liable for the "low emission zone" payments in London. So he got a T5 TDI, and loves it, says it's so good to drive, he wouldn't go back to having a car.
He bought the T5 as a plain van with no windows, then bought a kit to put cupboards, sink and fridge inside and then took it down to a place on the south coast for it to have two windows put in the sides and a proper rock n roll bed put in.
It's a pretty sweet ride now, perfect for him cos he's a surfer and is out in it most weekends.