I too have heard the reports about bad bus service at WL but we were there for 2 weeks at one of the busiest times (12/19/02-01/01/03) and the service was fantastic. We never experienced boats being full and passing by. Other than the boats to MK, we used the bus system exclusively and couldn't have asked for better service. There were no waits over 10 minutes, most under 5. Many times the bus was sitting there waiting for us as we walked up.
There were certain times that the bus did go to the GF. Chip 'n Dale Express explained it in a post as I could never figure out what the pattern was...
"Prior to 11am, WL shares with Grand Floridian. Post 11am, WL shares with Fort Wilderness, with the exception of DAK... which is GF all day long."
So, when they do go to the GF they aren't stopping at FW. We only went to the Poly once, and the bus driver recieved a call to do so. Of course they could change those routes at any time and I'm not sure it's still following the same routes. At any rate, whatever the stops were, the busses were extremely prompt and we had no complaints whatsoever. The WL busses were much better than the bus experiences we had while staying at the Yacht Club in 2000!