I've gone down for the race the past 5 years and am going again this year.
Crowds aren't crazy, but they're not light either. The 1/2 has 17,000 people registered, just to give you an idea. But w/ this race, there are a lot of local runners who leave after the race. Rides like Indy and Space will be around 45-hour wait. POC and HM will probably be around 20 min or so. Saturday night will probably be the lightest, b/c people will be sleeping early b/c of the race. And I would assume 1st hour or so in the parks, b/c people are running and back at the hotel getting ready. Magic Mornings will be cancelled for Saturday, b/c the 5k runs through DL. I believe they added it to Sunday though to make up for it.
The weather hasn't been bad either. But of course now that I've said it, we'll probably have a heat wave.
There was 1 the 1st year I was down there and it was 100+ each day. It was absolutely miserable. The next couple of years, there has been coastal fog in the morning burning off around 8:30 or so. Last year, there was no fog, but the weather was good. Don't remember exactly, but it hasn't been hotter than 75-80 since the 1st year.
For hotels, if you're going to go w/ that weekend, book asap. I know that BWPPI is already sold out for Saturday night and it will only get more booked as time goes by. As far as hotels/race noise, if you stay along Katella, 5:30-6:30 will be loud b/c that's the beginning of the race. The race start/finish is the parking lot at DLH and there's a DJ and some small fireworks at the start. The dj will start about 4 or so and go until 10:30-11. Staying at the DLH will be a bit loud. Also, depending on how thin the walls at your hotel are, you could hear people b/w 3-5 race morning if they are loud. Also, on Sunday, again depending on where you stay, plan extra time in the morning getting into the park. The last mile goes down Disney Way into DCA, (or did~ this year's map isn't out yet) and they will block off/monitor how many people can cross the old parking lot entrance. They'll give the runners the right away and let you cross when there is space.
In DTD, the restaurants will be busy for dinner though. Naples b/c a lot of people will be carbing up and ESPN Zone will also be really busy b/c it's the start of college football as well as the race. The same goes for some of the restaurants along Harbor. I would definitely recommend eating in the parks that night, it's easier and faster.
Overall, I would go. If you expect people to be there and know that the race is going on, it's not that bad. And depending on when you're leaving, like the OP said about traffic, if you're leaving Sunday, I would try to leave before 11, it'll just be easier and traffic will be starting to lighten up.
Sorry for being long, I just wanted to give you enough info for you to make your decision. Hope that helps!!
