If it were me, and this is just me, I'd switch. I'm not overly fond of CR, I understand if you want to spend most of your time at MK the monorail is tempting but really the buses are not that bad. Have you been to CBR and walked around? I've never been there, one of the few resorts I have not visited although I plan on fixing that on my trip next week. The reason I ask, is you hear a lot of people complaining about the sizes of some of the resorts and all the walking and until you've done it yourself you can't really gauge how you would feel. I was worried about staying at POR, one the buses and two the size. Neither was a problem, seriously I walked the entire perimeter and over to PORFQ in about 15 min, not walking fast and I'm not young. As far as buses, you aren't going to get away from using them no matter what resort you stay in unless you either have a car or you plan on only visiting the park that is closest to that resort. If you stay at any of the Epcot resorts, you are going to bus to at least AK, possibly MK. If you stay at the MK resorts, you are going to bus to AK, possibly HS. If you stay at AKL you are going to bus everywhere. For $3000, I'd tell the kids you are going to Disney, it's all good.