It looks like a nice home, but it is a pricey home given the location of your lot. You are right on the corner of Hampden which is very loud and busy as you mentioned which will require a significant discount comparing it to an identical house that is even just half a block in from Hampden. Also, at this price range, central AC is a must in my opinion (it says you have a swamp cooler in the listing).
You also have some new construction pretty close to your home that is going for just over $1MM that are not on the corner of the busy street which is some stiff competition for people looking for high end homes (800k plus). I think you would maybe be in the range of the comp at 4547 E Girard Ave. I know you have a lot more square footage, but you have the same bath count, one more bedroom, and they have a much better lot location in the neighborhood.
Not sure what other people think, but those are some of my opinions. In the end, I think the location of the home is your biggest thing working against you. I know for me, I personally wouldn't want to live on the corner of Hampden when I'm spending that much money.
Hope you have some luck getting this thing sold!