For me, I find roughly the first half of the three 1980 shows I’ve heard (6/29, 6/30, and 7/7) to be fairly enjoyable up through Trampled Under Foot. After that it starts to get very hit or miss, since Page’s guitar playing isn’t what it was even in 79.
To answer your other point, I feel almost the same way, except for the fact that I never skip the noise solos from 77, no matter how long and weird they are. The drum solos have always been hit or miss for me, even for the early years.
Out of curiosity, what other songs from 77 do you sometimes skip?