On long overnight flights, bulkhead rows are favored by mothers with children. In fact, the airline may book a family here because it's easier to prop up a temporary crib against the plane in front of the seats.
That may be fine for the family, but nearby passengers may be treated to the cries of small children. If your modus operandi is to sleep across the Atlantic, the bulkhead row may not offer a quiet ride.
On some flights, seats are automatically booked from the back to the front of the plane in that order.
So if you're assigned a seat in the back of the plane, don't automatically accept that 33C seat. Speak up and ask for a seat closer to the front.
You may not get exactly what you want, but you might end up with a far better seat than what the computer had given you.