EddieHollywood
In Manhattan Navigator each question has difficulty level (from nothing to devilish). Is it correct that moderate difficulty corresponds to the 550 score (avg score by official site)?
No non-official source is currently able to precisely match an official score. Take the classification you see as either a broad one or their best guess as to how difficult that question is. This is not meant to say that their classification is not correct. Come to think of it, the fact that it is so hard to make anything align with the actual exam is probably the reason that they haven't gone for a more precise categorization (the more specific the categorization, the greater the chances of error).