Epcotdude,
I ran both last year. I had already signed up for the RFTT then they decided to have the TOT race so I had to sign up for that one.
RFTT - typical daytime race, but at Disney which makes it special. I had a good time as this was my first race at Disney. The benefit to me is that they offer discount tickets to the Food and Wine festival. The food afterward wasn't anything special so don't go just for that

As with other Disney races, they have nice bling. I really enjoyed the weekend.
TOT - I know a lot of people didn't like this race because of all the issues. But, I really liked this race. Yes, the traffic was terrible getting there and that put a little dampener on the race. Originally it was to start at 9:00 then they changed it to 9:30 then because of the traffic they actually didn't start the race until 10:00 (scheduled start this year). This is not an issue except it limits the time in the park afterward.
I assume that will all be behind them this year. But, what a cool race. First of all it was at night. How often do you get to race at night. Not many locations can pull that off. We ran through the Sports complex that was all lit up. Very cool. They even had an off road portion of the course although it had rained a bit earlier and there were a lot of puddles. We ran through Hollywood Studios quite a bit actually. Then, after the race we got to play in Hollywood Studios for a couple of hours. Usually after a race everyone just splits up. Here there was something to do. I rode TOT and RRC a few times as well as Star Tours. Pretty much walked on. I think the extra cost for a family member to get into the park was $20 or $25.
So, I would and did pick the TOT race this year. We will probably do Universal Horror Night on Friday then the race and Hollywood Studios on Saturday. Last year we did the Mickey Halloween Party on Friday night.
whichever you choose, enjoy,
Duane