As for business class, that'll be the rear half of the last car of the 5 car train. Be sure to take advantage of the free non-alcoholic beverages as a BC passenger. It's a split cafe/BC car with 18 BC seats in 2 & 1 configuration. There's pluses and minuses for either side, in my opinion. On the '2' side, there's a fixed armrest between the seats that has shallow beverage holders, not so on the '1' side (my 17" laptop fills the pull down tray). I like the '1' side, but the lack of a beverage holder and the 5" or so 'gap' between the seat and the side of the car makes it more difficult for sleeping.
I haven't ridden in one of those cars, so I am somewhat curious about the setup....
Why do they have that gap you mentioned? Sounds like they could have put the seat as close to the wall as the double seats are, no? And had either a wider aisle, a wider gap between the double seats, or even wider seats, themselves....
I realize they are not going to change any of that at this point...but a relatively cheap enhancement, would be to mount a 'foldaway' cup holder in that gap, at each seat....