I always rent a car if I can afford it. I DETEST waiting in long lines for a bus at the end of the day, and then likely as not, I get to stand on the bus, too! Ferry/monorail to the TTC is part of the fun, as is the tram to the parking lot.
The best part of having a car is not having to walk back to your room after a long, hot day in the parks. My feet are sore, my legs are tired, and my back hurts. I LOVE having a 2 minute walk from my car to my room! I don't miss "seeing" the resort because we walk down for b'fast/coffee in the morning, then back to the room for toothbrushing and a last potty visit before hopping in our car and driving off to the park. After a long, hot day in the park, we are back in our room PDQ because we drive ourselves back to the resort and park right near our room!