L.Z.
Hi A.,
I have been to disney a few times and have a 3 and 4 year old. I have taken both a double wide stroller and the front and back stroller. I have also rented the strollers from disney. It is harder for the kids to see everything in the rented strollers because they sit so low to the ground and if it is crowded they won't be able to see through the people walking.
When we took the double stroller we couldn't go into any of the stores with the stroller because it was too tight and lots of breakables around in the store. The front to back stroller worked best (although I agree not the easiest to push around). It fits directly on the monorail if you are taking it and you don't even need to fold it up. When you go into the park they will open up the gate for you to push in the stroller so you shouldn't need to fold it up for it to fit through the gate. In a crowd it is easier to get through with the front to back stroller because some people are not considerate enough to move over and make room. Everyone is too excited to get to the next attraction.
I never had a problem with losing or having any strollers taken from us at the park. That should not be a concern although I have heard of it happening outside of the park. Hope this helps and I hope you have a great time.
L.