I have done Jersey week 2x, the last time was in 2008. The crowds are not really there because of Jersey week it there because of the Food and Wine festival, Master of the Arts and the beginning of the Holiday Decorations. I found Epcot to be the worst, meaning in the Countries there are just a lot more people walking around. I really enjoyed it at that time, I am going back the 4th-11th. Master of the Arts affect DTD, but I think it might be later this yr, If I recall right I will be missing it by 1 day. All in all the crowds are not that bad.
Have Fun you will be in Disney!