Row 17 or 24 in Coach Cabin on 777-300 Aircraft
I have flown a couple of long legs seated in row 17 in the 777-300 aircraft where that is the last row in the forward coach cabin. (Seats 17A, 17B, 17D, 17E, 17F, 17J & 17K.) My comments would also apply to row 24 in those "small business class" variants of the 777-300 where that was the last row in the forward coach cabin.
As the original poster notes, the seats in row 17 are very close to the lavatories. Very close indeed. Those facilities are used by everybody in the forward coach cabin, plus everybody in the forward part of the next coach cabin. In other words, those lavatories are *VERY* busy.
Usually the lavatory line extends aft and there is a little knot of people just behind the bulkhead and in front of the exit door. That wouldn't be so bad for the folks in row 17, but unfortunately people also tend to bunch up immediately outside the lavatory doors. I don't know why they think hovering 18 inches from the door will shorten the wait, but apparently they do. When that happens they end up hovering over your shoulder. If you have an aisle seat this is particularly annoying.
Moreover, on my legs between Doha and Bangkok I noticed there seemed to be a significant number of passengers who were less than familiar with standard lavatory operation. Some were baffled by the mechanism on the lavatory door that locked it and displayed an "occupied" message to those waiting. Several times the flight attendants had to assist passengers who had locked themselves in the lavatory and couldn't figure out how to unlock the door. There were also incidents where a passenger would enter the lavatory without locking the door, after which the next guy in line would try to enter too -- causing many colorful international hand gestures. Finally I saw quite a few parent/child pairings who seemed to take an inordinately long time in the lavatories. Again this caused people to congregate in the vicinity of the lavatories, to the detriment of those seated nearby.
Bottom line? I think Seatguru is correct. On the 777-300 those seated in the row just in front of the forward coach lavatories will definitely be bothered by the crowds.