The Grand Tour is designed for what its name says - a grand tour. It is not designed for families, soccer moms, weekenders, entertaining guests, etc. It is basically a two person Class B motorhome that should be much more comfortable and versatile for staying out on extended trips by not wasting space to accommodate any additional people or try to be all things to all people. If that is not your style then it might not appeal to you.
BTW, there are limits to design between the back wheel wells and the cab. Not much can be gained for all the stuff that goes there when you extend the van in the back 16" expansion. What you get is possibly longer beds and definitely quite a bit more storage. So, with the Grand Tour eliminating the passenger captain chairs that space between gets better use for two people especially if you don't or don't intend to carry passengers. So, if you are on a grand tour such as a 2-3 month trip to Alaska you should enjoy it much better than with the Lounge.
2015 Sprinter Class B Camper Van
(Former 1971 vintage Airstream Owner)