Dear odonacer,
I understand that you are upset about the waiting game, than follow my opinion:
First, you can not make a deep (identical) time comparison with others forum mates, the spread-sheet is to get an idea about the time and,
Second, the program never promise an exactly period of time to process, in this way, my opinion is that you never consider the "delay" position... Hope you can understand this, if they did not promises a time, does not exist a "delay"...
Never the less, you can write a letter for them, but this is can be tricky, if you will not get the right "position" on the letter, this action can affect your process... Some people here in the forum get experience about this, is better to hear something from them also.
Hope this could help!