Stayed onsite without a car once and the above experience was the rule more than it was the exception. I wouldn't go to WDW without a car, I would actually stay home first. That's how pro-car/anti-bus I am.
This, however is an unending debate. Pro-bus people tend to use the same arguments:
They never wait more than 2 minutes for a bus (I don't buy it)
We waited sometimes 30 mins for busses
Buses are so much more relaxing (crammed in like sardines with the smell of BO wafting through the air)
No BO I ever smelled must be a Boardwalk thing? Also only 2 times in a 8 day trip were we packed in, DTD and lightning forced a bus from HWS to the boardwalk so there was a buildup of people by the time a bus came.
I don't have to worry about getting lost (there are more direction signs at WDW than just about any place I've ever been)
Sorry but even with 1,000,000 signs there is a chance of being in the wrong lane, taking a wrong turn, or generally having some moron driver not let you into the lane your supposed to be in....
I don't want to have to curb my drinking (I'll give them this one but it's nothing that would affect me)
Thats fine if it doesn't affect you but its nice to not have to think about it at all, especially when you do 1 table service meal every evening
Disney transportation is free (I can't argue with this one but you get what you pay for)
Its free and a great service from my point of view during our last trip based on staying at the BoardWalk only issue is Swan+Dolphin gets to ride the same busses
Bus people can't be convinced that a car is better and car people stay away from the buses. They're just different breeds.
I feel in the end it comes down to what someone else said earlier in this thread about what is faster?
-Is the bus pulling up as you walk to the bus stop?
-Is there extra traffic you have to deal with?
-How far away do you have to park from where you are going? (MK has some far out parking areas from what I saw)
-Is the bus stop so full that it will take 2 trips for you to get on the bus?
-Does the car get a flat tire or do you get in an accident?
I can see why people would want cars and I can see why people want to ride the bus.
For us it comes down to:
Cost (20+ a day, $30 if we pick it up at the airport which is the biggest benefit for us) vs value
Time (sometimes the bus is likely faster sometimes the other ways its not like your always saving time)
Location (we stay at the boardwalk so 2 of the 4 parks we walk/boat to and MK we will walk through Epcot sometimes to catch the monorail while picking up a snack/lunch in epcot)
Busses were above average last summer, we waited less than 5 mins a lot and over 20 mins only 1-3 times, we also were not really "packed" in except for those couple times we had long waits
Note - This was on our trip last July 7-15 during resort levels 7-9