Not there now, but we have been in WDW lots of times when MK monorail wasn't running. Buses from the TTC to MK were actually faster than the monorail for us.
Buses between the monorail resorts and Epcot are not so great. More than once- part of our group drove from Epcot and part of our group took the bus. Car beats bus by almost TWO hours! (leaving Epcot about 8:45pm!)
If you don't have a rental car, you might wish to add one!
Other times, the bus to MK/monorail resorts was also oddly slow. One time, we were At the MK bus depot, but the driver couldn't pull to a curb, and wouldn't (couldn't?) let us off. We just at there for a solid 15minutes! People were NOT happy.