I'm going to say a B, give or take a plus. I really like the series and how its using the idea of a Parker family to drive the story. On the other hand, I'm not sure it quite as the same drive. It somehow feels like it knows that it's an AU series, unlike, say, USM, which read like it was the real Spider-Man title, if that makes any sense. I'm also not sure if the compressed writing style does that much for me.
However, given that I like the basic premise and it has good art and decent writing, any complaints are just nitpicking.