We've always had good luck with the buses at CSR.  The resort is centrally located and AK is probably only 5-7 minutes, same with Epcot and DHS.  MK is the farthest and I'm sure KatMark's timing of 10 min is spot-on.  We've rarely waited more than 5-10 minutes for the bus we want, plus the pick-up locations at the parks seem pretty favorable.
There are 4 bus stops at CSR, #1 is at the main building, El Centro, #2 is at Casitas, #3 Ranchos, #4 Cabanas.  The pick-up order to go to the parks is 2, 3, 4, 1, and drop-off is the same.  (Going to DTD, it's 1, 2, 3, 4.)
We've had great stays at CSR and look forward to our next one in May!