People have tried to answer all of your questions. I don’t think you are going to get a specific review of Row 20 seats. The economy seats on the 77W have been pretty thoroughly reviewed in this thread. Row 20 is a bulkhead, and you are not going to be able to store items at your feet for takeoff or landing. If that is an issue, move back a row or two. As for screens - in row 20 they are flip out. The oldest of AA’s 77Ws are about 12 years old; the newest maybe 8 or 9 years old. So yes, the economy seats and screens are that old. The 777-200s are older and smaller, but are still used on long haul, though generally not across the Pacific, which are usually (exclusively?) 787s or 77Ws. Finally, you get to board with Group 5 - after business class has boarded - not before.