Hi! We were very concerned about the bus transportation at WL as we had heard some pretty bad reports. I have to say that we were exceptionally pleased with it!
Our first night we went to MK for Spectro, and had to wait 2 boats. Our wait was about 25 minutes, and the boat ride itself was 12 minutes. We took the boat the next morning and found the entire trip to take 7 minutes (2 min wait and 5 min ride). Needless to say, we used the bus the rest of the time. BTW, from our courtyard view room, we could watch hords of people walking to the dock each morning to catch the boat. There was never more than 1 other family on the bus. AND, the bus stop at MK was the # 1 stop, closest to the turnstyles.
Our experience with Epcot was equally efficient. We had to run to catch the bus at about 8 am as it was at the stop at WL. I believe we stopped at FW on the way to Epcot, then on to Epcot, I believe the whole ride including that stop took 20 minutes. On the way home at closing, after walking from our Ill. viewing spot near Mexico, we were on the bus by about 9:25 and home by 9:50. The next night we were on the bus by 9:30 after waiting one bus because it was full (wait time was about 7 minutes). We were home by 9:53 (we didn't take the bus there that am, we wanted to tour monorail resorts, so took a monorail).
My thoughts are if you are going and coming at busy times, early am and at closing, the buses are very efficient. In the middle of the day, you will probably have longer wait times. (We found the buses great for DHS and AK also, BTW. We shared with GF to those parks, with a stop at GF going to park and WL being 1st stop coming home.) DTD was a different story, but that seems to be the case with all resorts, not just WL.