With little ones, we spent most of our time at MK and Epcot. We took the monorail at both of those and didn't mind the stops because our kids enjoyed the monorail ride so much. We actually didn't have to switch to go to Epcot because you can easily walk to the TTC from Poly and get on directly there.
We ended up driving our car to both AK and HS because we didn't want to deal with the buses. We just found it very hard to hold hands with little ones and carry a diaper bag while one of us had to fold up a double stroller and try to get everyone on the bus. We experienced that in 2008 when we stayed at the Wilderness cabins and that even had an extra bus due to having to get to the end of the campground and that was our most disliked part of the trip.
Actually, this is making me reconsider our reasons for staying at Poly last year. We will still be in the same situation with a double stroller and even if we don't have a diaper bag any more, we will still have a bag of some sort. Our youngest will be 3 on our next trip so hopefully he will stay with us a little better but I don't know about my daughter who has Down syndrome (she will be 6 by then but she doesn't understand danger and she will run away from us). It just makes the whole getting on the bus process very difficult.
Hmm...something to think about.