What a mistake, the crowds were awful! I hate Disneyland’s Halloween Bashes! The park closes early (6 or 7 p.m.) three days a week (MWF) which means that even if you are at Disney California, you are flooded with all the people from Disneyland who must leave the park and are not part of all the sold out Halloween Parties; so much so you can barely move in Disney California! Disney must sell some packages because the parks (both) are crowded every day of the week! Disney was not at their best - Metal detectors, ride close downs all the time (Indiana Jones, Space Mountain, Ariel’s Undersea Adventure, A Bugs Life, etc! Some days they just randomly decide not to issue Fast Passes for popular rides like the Tower Of Terror, so if you want to ride the ride you get to stand in line for an hour to an hour and a half (all day long). With Fireworks (non Halloween Bash) ONLY on Saturday and Sunday, if you want to see then you have no choice but to select a crowd level 9 or 10 for one of your days, which is awful. For the first time in my Disney experiences I did not get my money’s worth. Also, the Pixar Play Parade in DC is old and short, the same parade they had three years ago, very disappointed!
Yeah, I’m sorry to say I had the same experience. We had gone during October multiple times in the past (even after the advent of the Halloween party) and had a great time - low crowds and nice weather. This time, although Touring Plans had predicted crowds of 3-4 level, what we encountered was 10/10!! Cheek-to-jowl crowds and hour-to-90-minute waits for EVERYTHING, even first thing in the morning, even the “lame” rides. Sadly, until there is a more effective way to predict crowd levels, I’m not just saying never again in October, but never again, period. And this means something coming from me, as Disneyland has always been one of my greatest joys in life.
We are going Nov 2 and 3rd. I hope we don’t have 10 crowds. 
I believe that will be a great time, as long as the Halloween Bashes are over!
I was also disappointed in the Crowd Tracker, which after my experience is meaningless because it was not an accurate indication of crowd levels at all! Perhaps mid September or early November would have been better.