IMHO, after Swan/Dolphin, I think the DS hotels are easily the most convenient "off-site" locations. The bus service is not as convenient as Disney Transport, but it's far more convenient and reliable than any truly off-site hotels. It will take longer to get you to your destination, but it does run on schedule throughout the day, and you can use it as much as you like at no extra charge.
In the afternoon and evening, you also have the option of walking to DS and getting a Disney bus to CR or BC for MK or Epcot. Of course, some of the DS hotels are a much shorter walk to DS than others.