My latest experience is very recent: 744 on the weekend, back today on 772.
Echo all others, select the 744, feels a tiny bit roomier in the seat, lavatories are equally rocked down (they didn't even have paper cups today).
Pluses that I see for the 772: Air quality is (felt) less dry and the floor is not as noisy/ movable as on 744. On the latter I felt every FA passing by.