I’ve gone from an Audi A6 to a VW Kombi, although its not a car derived van that you say you are interested in I thought I’d give you my thoughts.
Before I got the van I was a bit concerned that it would feel a bit agricultural compared with the Audi but the VW is a nice place to be, drives well and is quiet on the motorway and at speed. There is obviously a difference between the two vehicles but nowhere as much as I thought there might be. It is stable if its windy but in very high winds you have to be aware when driving on exposed roads and overtaking trucks (might not be an issue with a car derived van). I have the 140bhp version and while its not going to break any land speed records but when its empty or with a secured load, it can be fun to drive on the right roads without collecting bonus points from police officers. It is a 80 litre fuel tank and I can get 650 miles out of a tank, slightly better than my old A6 but with a similar driving style.
I have a few extras on it (upgraded interior, air con, reversing sensors, privacy glass, DAB radio etc) which help make it a nice place to be. I bought in new and I tend to keep it spotless which again, makes it a nice place to be.
I have done a few longish trips in it (300 miles +) and I haven’t been knackered (I had a Vauxhall Astravan a few years ago and after a long drive I would end up being quite tired). Friends and family that would not usually go in a van have been surprised and impressed (or are they just being polite??) with it. It’s great for biking,2 bikes straight in the back, more if you take the wheels out. I haven’t been camping or slept in it yet but it ticks all the boxes with the space it provides. So, no regrets and I don’t feel the need to buy a car to provide thrills or respectability.
You don’t say what your budget is (as my old Astravan wasn’t great compared to the VW) but I hope my observations help in making a decision. If you go for it I reckon you wont regret it.