September traditionally has very low crowds. The humidity, rain, hurricanes, love bugs, high temps are all potentially a part of your visit at that time of year. Not to say that we didn't enjoy our visits in September, but it's a time when you HAVE TO keep a bottle of fluids in your hand and drink all through the day! It was a fun time for sure, but it was important to pace ourselves, be prepared to take a seat inside now and then just to cool off even though we would rather be going 24/7.
MNSSHP was pretty cool, but being that we don't have kids, it's not a must do for our upcoming trip.
From all that I have researched about October, the temps are lower, less rain, no love bugs, still can be humid, but not as bad as September. I am looking forward to the F&W festival and being able to celebrate my 40th birthday at WDW, when I get to it in November.
The choice is yours, but I think that either way, you can certainly have a lot of fun! Maggie
PS. If you decide to come in October, check in over at
http://www.disboards.com/showthread.php?t=1360866 and I will add you to the Official October List! Maggie