I’d agree with earlier comments about older vans – they look nice but are a hobby rather than viable daily transport, particularly if you are doing lots of mileage.
Poptops = very small £3k tent stuck on top of your van. Never appealed to me.
Each to his own but I would consider Increased headroom when camping whilst still being able to get into any car park to be a big advantage.
When you are struggling out of a wetsuit / wet riding gear in a bitter northerly gale in an exposed carpark, the ability to stand up in the van is also very welcome.
Also provides bedroom for our son and storage for bags etc when camping.
Wouldn’t be without ours personally.
I know of very few rust issues with T4s which have been looked after – they are pretty bomb proof. Admittedly the T5 is a better drive, but I think the T4 is still pretty good too. Avoid the 2.4D and normally aspirated 1.9. Get a TDI if you can afford it, but the 1.9TD is fine if you’re not expecting a racing car.
We have a ’95 1.9TD Westy California. Fantastic van. We paid 11.5K for it 2 years ago, but I know I could get the same back if I sold at the right time.