We were there 10/25 to 11/3 last year.
It was a little more crowded than it used to be, but totally manageable.
Epcot during the days did not feel crowded at all throughout World Showcase and at night on weekdays was pleasant also. The smaller rides had less than 30 minute waits, and we just did rope drop for Test Track and fast passed Soarin - easy.
MK on party days was great. MK on non-party day was still great in the morning, we have pics of empty walkways, and not even too bad in the evening, but we did feel the crowds during the HEA show - like, can't move, shoulder to shoulder, almost made me crazy crowds - that was the only point in our trip that we felt annoyed. Day after Halloween felt empty! Sat right down on Main Street right when afternoon parade started - my avatar picture is from that day!
Animal Kingdom felt crowded in spots, but honestly with no fast passes we got on Everest, Dinosaur and Safari with waits under 30 minutes both days we were there. Love that park.
DHS - we only went on a Saturday for a few hours - it was fine, did not feel overly crowded.
We went to the party on a Thursday (10/26) - AMAZING!!! We walked on every ride, with only a 15 minute wait for Haunted Mansion. No lines for candy either!!!
Would definitely choose that week again if we were to go back again in October. But we've been in October a few times, so now we want to go in May.

Plus we had a cold snap during this trip - ugh, that put a damper on things!
Overall, an excellent week to go to Disney!!!