We just left Pop and had zero issues with any transportation. The key is to get to the transportation areas early. The day we checked out the line was super long to get to MK, open time listed 9 and they got in line at 8:30. We never waited longer than 20 minutes in any line to the parks at Pop. Here is what we did
--MK open listed time 9. Got in bus line at 7:20. Should have gotten there earlier- probably 7. We got on the 4th bus. In line for seven dwarfs at 8:20. Waited 15 min to get on ride. Then walked on Peter Pan ,Big Thunder, and Haunted Mansion.
--HS open time listed 9am. We got in line for Skyliner at 7:40. Arived at HS at 8:20. The line moved super fast. We were able to walk on Millennium Falcon and Toy Story Mania.
--AK open time listed 8. We got in line for bus at 6:40 and was on first bus. Arrived at park at 7:05. We were the first resort bus to arrive. Walked by ourselves to Pandora and first in line. Walked on to Kilimanjaro after that.
--EPCOT open time listed 11. Went to skyliner at 9:05. Get off at CBR and we walked to Riviera instead of waiting just bc it was so nice. The line at CBR we would have been 5th. Started running skyliner at 9:55