So following the test drive the question I need help with has changed a little.
We really liked the Shuttle, was much better to drive than expected. That plus the nightmare our first attempt at carrying kids and newborn in the 7-seat Kodiaq we already have confirmed we would likely be using the van more than first planned so we settled on spending the extra and going for the 199 model.
However I then spotted for the first time that the T6.1 Caravelle comes in a LWB spec, I had previously ruled them out as I thought they were only SWB. We don't need the 9 seats, 7 will do and I'm guessing the Caravelle could be even more practical as presumably the rear bench seat can be slid further forward than the fixed location of the rear bench location on the shuttle.
I priced one up and I can get a 150BHP DSG Caravelle LWB with leather interior for less than the 199bhp DSG Shuttle LWB, both are T6.1 models, pre-reg, delivery miles models. If the Caravelle is genuinely a lot more refined and comfortable I think we would value that over the greater power.
I had a Caravelle rental booked through Hertz Prestige only for them to tell me a couple of hours before they actually had none on fleet and were giving people Merc V-classes instead.
So putting it out to the very helpful people on this great forum - 150BHP DSG Caravelle LWB or 199BHP DSG Shuttle LWB??