Having said that, I have owned both the current and previous shape 6 and whilst the narrower boot opening can be a little awkward sometimes, the boot is huge and the rear seats fold flat giving almost as much storage space as the estate version.
Being an owner of the 13-on M6 Saloon, I would not say it has a huge usable boot especialy when you have a spare wheel in situ. You cannot fit 2 pullman suitcases in the boot, nor a cooler/refrigerator standing up. There is a 4" box section under the parcel shelf which prevents placing two suitcases on top of each other. You do not want to be going on holiday with cases sat on the backs of the rear seats they should be in the boot out of sight. I bought a grasscutter and it was too large to fit in the boot, but just managed to squeeze it through one of the rear doors. Had the car been a hatchback none of the above problems would have been there.The Ford hatchback looks a smart shape, but I will not buy a Ford. The M3 has the hatchback and thats only a shrunk 6.
My previous car (not a Mazda) was a hatchback and smaller and I didn't have trouble loading the boot for holidays, there was always spare usable space .
Why they call cars 5 seater when the rear middle space is not actually a seat. If you had 5 adults going on holiday in most cars you would have trouble finding space to put cases. When the wife and go on holiday we always dress for dinner, dresses, suits and ties. Recently we were on a dancing holiday and I had 3 suits and the wife 5 dresses with shoes to match, plus dance shoes and there wasn't a Black Tie night either.
I saw a video from a journalist touring Spain, his suitcase wassmallwr than I would use for a long weekend. Obviously he didn't stay at any decent hotels.
Though I have managed to fit 22 bags of horsemanure in the car with the rear seats down. The other design failure is lack of rear lighting when reversing. They must have some strange ideas and driving practices these Japs.