We stayed at BWI for seven nites last year and took the bus to Downtown, AK, Mk,.
We had no problems with the bus service other than very occasionally we waited for longer than the 15 min that we were told the buses run.
The one thing you might find that you do not like is the loop returning from the parks or Downtown is the fact that BWI is the last stop on the loop. Swan, Dolphin, Yahat Club, Beach Club and then BWI.
BWI is a fantastic resort. Great cast members and super location. We walked to Epcot and MGM early in the day and then took the boat back to BWI later in the day. The boat dock is right in front of the entrance.
Do not let what you have heard about the buses stop you from going. We were there end of Sept and beginning of Oct last year and are going first week of Nov. this year. Go and have a magical time !!!