The whole dashboard and cockpit. cheap plastics, no glove box, no top dash box, removed 1.5l bottle holder, no more textile on the doors, awful-looking steel wheels.
Also the extra sleeping mattress in the back got thinner - I haven’t tested the difference yet as we’re still waiting for our T6.1 to get delivered.
The re-done knobs work better in theory, but in practice they don’t work well (don’t always close perfectly where they should) and again a flimsy construction, just different way this time (except the "cupboard sliders from the T6, they were also a joke with the ducttape in the back).
The old T6 Ocean GREY trim is no more, if you select the same stuff for a T6.1 you get around 6-8k pricier than a T6.
Of course there are better things in the T6.1 like a digital cockpit and the new camper unit, the reclining rear seat and the mattress support upstairs… but not everything is better, just because it’s newer. 