The 1st week of October is pretty crowded. Especially compared to the weeks before Thanksgiving. I went the 3rd week of November last year, and going again this year, and it was awesome!!! The crowds were low and the weather was great!
October is fun, crowded and hot! I liked going during the F&WF, been twice. It's just now I've discovered November, and it's going to be hard to break from this time of year.
Either month, you'll have a blast. If you go in October, plan carefully. But the guidebooks, and read lots of past Dis threads, they help, ALOT!