Yes the seat is the same, but where you rest your legs when sleeping (ie the buddy seat) is narrower.
really did you actually measure it.
I used a non-scientific way before to measure it (ie. the Discovery magazine) and appears to be the same (ie. the buddy seat width and length) as other seats. But do feel the elbow room to be slightly more constricted.
Anyway, these seats will be gone soon and all the 77W F Class seats share the same dimension.