I know this thread is about a month old, but I just wanted to add to the other posters here and say, for the price, we thoroughly enjoyed our stay at the Renaissance WorldGate. The rooms were clean and we had a top floor awesome view of all the Disney firework shows at night! I got it for $40 through PriceLine. I probably overbid after looking at the bids on the biddingfortravel boards, but it was still a fantastic deal for an October stay (during Halloween). We too drove to FL, so we didn't make use of the shuttle. My understanding was that they only made one dropoff (at Epcot maybe?) and that you would have to use Disney transportation if you needed to get to a different park. So, I guess if you do use the free shuttle, you just want to make sure you time it right. Also, if you end up renting the car, be sure to ask about the oft mentioned "secret entrance" to Disney. It's not really secret at all, but more of a locals only road that will probably get you to the park entrances quicker than the main routes, especially during the peak season.
Good luck!