I agree that not having someone next to me while seated in Y is more comfortable than having additional legroom only - I'd rather sit in a regular AB, DF, or KL seat on a 767 with no one next to me than in a bulkhead with someone in the adjacent seat.

I recently saw a website for an airline seat manufacturer that had designed a 3-3-3 configuration, with a seat width of 18 or 18.5 inches and 33 inches of pitch. The increased pitch and width were created by placing the seats at an angle. The angle also allowed each passenger to have two armrests. If I can find the website I'll post it.