T6 Transporter/Multivan/Caravelle

[Tornado T5]

I thought Mercedes already had both SWB and LWB already for many years or is this in a new shape ?

Overseas there are SWB, MWB and LWB Vito Van and Vito Crewvan versions.
In the last two Vito models the Crewvan only came in MWB length in Aust. For the current 447 Vito a LWB Crewvan adds about 33cm of interior cargo length behind the 2nd row and matches the VW Transporter LWB. The Vito has superior rear seat flexibilty.

[Sunny43.5]

Thanks for that I haven't really been following Mercedes vans so it was new to me .

[irsa76]

One thing I've noticed about Mercedes dealers, is that they tend to treat vans as second class citizens, experienced this from both sides as a dealer mechanic and later a customer, albeit a company driver but then again the company I work for was at one point the largest Sprinter customer in the world. To the point "my" Sprinter was a T1N SWB 313 Sprintshift 3.5t, a model not available to the general public, had a few other interesting options such as no windows, 3rd brake light, rear step and 100L fuel tank. Local dealer still messed us around, know a fair few other Mercedes van owners who had the same experiences.
Personally I'd have a look at Renault offerings, only considering a Multivan because Renault won't do a passenger version of the Trafic for Australia and the Citroen Spacetourer hasn't been confirmed for Australia.

[Transporter]

Thanks for that I haven't really been following Mercedes vans so it was new to me .

I'd stay away from MB, the built quality is iffy, body and mechanical.