Caribbean Beach is centrally located, which provides quick transportation. As stated in previous posts, the Disney/MGM Studios is about 5 minutes away. Epcot and Animal Kingdom are about 8 minutes, and MK is about 13 minutes. Add about 3-5 minutes for the EC, AK and MK bus if the bus is an "A-Side" bus, as traffic on BVD can slow things down.
There are seven stops within CBR. The stops are:
A Side:
Martinique
Calypso (Old Port Royale)
Trinidad North
Trinidad South
B Side:
Jamaica
Aruba
Barbados (Custom House)
If the bus is an A Side bus, it will do M, C/O, TN, TS, J, A, B/CH.
If the bus is a B Side bus, it will do J, A, B/CH, M, C/O, TN, TS
A "B-Side" bus can do a round trip from the Magic Kingdom in about 32 minutes. This includes travel TO the resort, all 7 stops, and then travel back to the MK. So, you figure an average of 15 minutes.
Also, note that CBR uses MOD (Magic On Demand) in the morning, so if a bus fills up prior to finishing all the stops, they'll dispatch another bus. In the afternoon, busses are Flex dispatched to alternate which side. Often times, you might see one MK bus, and then another MK bus 2 mins later.