Both the Field and Stadium ESP seats are advertised to have 33 inches of legroom. These ESP seats have 44 rows, going back to the Stadium Club under the press box (26 rows of Field and 18 rows of Stadium.)
The new benchback seats have 50 rows going back the same distance, so, I would expect them to have about 44/50 of ESP Field/Stadium legroom or about 29 inches of legroom. These same benchback seats extend 58 rows on the edges of the press box structure, going all the way to the rim of the stadium.
It looks like the rest of the rows of the stadium extends to the rim with about 74 or 75 rows. So, I would expect about 58/74 of the benchback room or about 23 inches of legroom for the rest.
Leg room? How about butt room? Has the width of the seats been widened? The original seats were designed for much thinner fans. Trying to squeeze in between two sweaty fatties and being immobilized for the whole game is a very unpleasant experience.