This article is about a 727, but anyway, the 747's I've flown on, always in coach, had a 3-6-3 seating arrangement with two isles. They're pretty comfortable if you can have only 2 in the 3 seats. If it's not crowded you can bed down pretty well in the 6 seats in the middle.
Nowadays most planes are usually packed and so not so comfortable.
The 727's had a 2-3 seating arrangement. They were almost always packed and I always ended up in the middle seat between two 300 pounders - miserable.
I know it is, was just sayin
I just looked at the pictures and it has 3-3 seating. No wonder I always had to sit between the fatties. Some plane that I used to fly on though, had 2-3 seating.