I have a 2018 LWB Vivaro Limited Crewcab, which i've converted into a rather spiffing day van, with king size R&R bed, hot water, shower, cooker, large fridge and loads of off grid power. It's the best driving vehicle i've owned, brisk, very quiet and smooth and returns over 40mpg on a run.
It has sufficient bells and whistles to make life aboard comfy, whereas the Fords have loads of kit, some of which is likely to go wrong at some point in the future, especially the heated seats. I do like the Custom's, but i'm tall, so find they have a lack of headroom. The T6 is ok in that department, but the legroom is very poor.
My R&R is set back a little, so rear storage is reduced, but i can get my barge in on an angle, with the front wheel removed. It is a seriously comfy, relaxed and quiet drive. I did the Exmoor Explorer earlier this year, drove to London for an ebay purchase afterwards and then drove back home to Devon, all in the same day. I wasn't tired and could've easily stopped for a kip if I had been.
I also looked at the offerings from other suppliers, but if you look at 10 year old Crafters/Sprinters and Vito's, they're all bleeding rust from various points. If you look at a 10 year old Vivaro, they pretty much all look mint, which is down to having a galvanised body. Those early models did have a reputation for gearboxes made from chocolate, but the later versions don't have many reported faults, other than the injectors seizing, which is due to the small drain holes in the windscreen trough getting blocked and the water flows over onto the head. Other common issues on the Fords/VW's are dual mass flywheel failures, drive shaft failures, numerous electrcal gremlins, rusting door hinges, leaking windscreens etc. Take a look at Honest John's website and the list is very long for both vans, but the Vauxhall has barely a bad word against it, hence why I bought one.
I have been hearing good things about the new Crafter, which is being built back at VW, but is a lot more expensive than my Vivaro, for only a marginal increase in space. I also drive a Sprinter for work and it's rattly, has a noisy diesel engine, lacks modern car comfort and refinement, so I certainly wouldn't buy one of those.