We take our Dreamer double jogger each trip to WDW (about 3x a year) and we LOVE it there!! However, I will say we tend to stay at the Epcot resorts the most often so we can walk or boat to MGM and Epcot, and we also utilize the monorail to go to MK, so we do skirt around the issue of taking the jogger on the buses. It is the quick-easy-fold, so it's not a huge ordeal to fold it, but it's more the size and taking up so much room on the bus. If it's a slow season, then it's normally fine on the bus, but we just prefer to walk, boat, or monorail to parks.
The only tight squeezes we have are the entrance and exit to MK (we can make it through, but it's tight) and then also the boat dock at the Boardwalk is tight.
Our thinking is that the most important thing in Disney is to have the kids comfortable. Our twins love, love, love the jogger as the seats are padded and recline and have nice big canopies. Each seat also has pockets so the girls can store some toys and their sippy cups.
Oh, I should say the Dreamer is comparable to the Bob. Here is what it looks like:
http://www.dreamerdesign.net/d_jog_dlx.cfm