Bulls in september are less predictable, but there's nothing like screaming bulls. Biggers bulls can be hard hunt in the rut. Once they establish a harem it's hard to get close. The warm weather is a bonus. There are few travel or camping concerns. Getting the meat out unspoiled can be a work-around.
I'm not sure what states you plan to hunt, but the weather in Wyoming in November can be warm or it can be so terrible as to ruin your hunt (closed roads, deep snow, fridged temps). Deep snow can seriously limit access and camping can be uncomfortable. On the flipside, I believe bulls in the winter phase are easier to hunt if you can locate them. They're predictable. They'll typically pull back up to a bit higher elevation where they have good feed and cover. If they are not bothered, they'll hang out in the same relatively small area. They'll also travel together, so you typically get to see a few bulls together. The November coat on a big bull is beautiful. Sometimes finding these rut-scarred beasts can be a challenge. Once you find em you're chances of seeing them again are relatively good. Meat spoilage is not an issue.
That probably didn't help matters. I've been in on both kinds of hunts and both are fun!