Originally Posted by
minnyfly
That equation is simply not true, particularly in business cabins. Personal space is significantly independent of density. That's why some airlines have moved past herringbone configurations. There's more efficiency to be found.
Sorry, that makes no sense at all.
More people in the same space may be more efficient but it is also higher density. That's just basic physics.
I've flown virtually all the major configurations in J, and it is precisely what you describe as the "inefficiency" of reverse herringbone which makes it more appealing than virtually any other J configuration. From the passenger's perspective less seats in the same space = better. That's the main reason that UA GF is "better" than UA BF.