I am in a similar situation... and have a couple of thoughts for you: (I already own a 5 seater 2017 X - with lots of experience in it, but I don't have any experience with a 6 seater).
- If you keep the last two seats down all of the time in the 6 seater (based on spacing and the web images), I think you end up with the same trunk size as a 5 seater. You would just have a 4 seater from a practical standpoint.
- The open space between the two captain seats is all you have for longer items - they would have to be fairly narrow.
I have thought about it often... the end result is that I really don't want or need a 6 seater - I definitely don't have any use for the 3rd row. And, looking at the captain chairs (I have looked through the window of a new X) - they really don't look that great - no armrests... just kind of a basic seats. Given that I intend to keep the car for quite a few years, I am just going to wait for the vehicle I ordered: An LR with 5 seats.
By the way, if they call and say the 5 seat LR option is cancelled - I would accept a 6 seater, as ultimately, I do very much like the X as a vehicle.