OK. I just completed my NRT>DTW. DM traveling in C+ 747.

30 min until boarding: A small crowd already camped out around the gate even though there is plenty of seating (Gate 26).

15 min out: GA announces that boarding will commence in 15 min. half the seated people head to the gate.

GA announces pre-boarding of people needing more time: Most people out of their seats.

GA announces pre-boarding of people with strollers and carseats: I get up and head to the gate. The crowd is huge but one GA with signs tries to organize with Prem directly in front of the SP line, SP to the right of that, zone 1 to the far right, zone 2 and 3 to the left. No gap in between zones so it's just a big mass.

GA announces "Business and Diamond Medallions may board": Movement up front but no one moves in the outer 50% perimeter. Have to push my way through the layers asking if the people are boarding in this zone. Most are not. Finally get to the middle where everyone is moving and no gaps. I assume I'm at end of Zone Prem. Move a few steps forward closer most people stop advancing. At this point, 70% are not Zone Prem but just planted in front (about 10 thick from GA!). Have to push my way through until I finally reach the end of Zone Prem at the SP lane. At this point, smooth sailing. The guy in front of me comments that you have to be fullback to board this plane.

Go through BP check and J and Y split into two separate jetways. At this point, straight shot to my seat. I settle in quickly and estimate 30-40 DMs in Y. Even though it was chaotic at the gate, the 100% full flight boarded more quickly than normal, probably because all the diamonds were able to settle in parallel with BE instead of the extra 5-10 minutes if sequential. This change is definitely a good one for the boarding process. The gate lice infestation is another matter altogether. I think things would go even better on 777/767s.