The last two times we stayed at POP we used ME.
The first time we did not share a bus. We waited in line at MCO for 45 minutes to get on a bus since it was so busy.
The second time we shared with AKL and CSR. We were the first stop. We walked right on the bus since there was no waiting at all at MCO.
Both times POP was the last to be picked up on the way to MCO for the return flight (I like to call that the "Bus Ride of Disapointment")
If I remember right you can see the entrance gate to Disney from POP. Please correct me if I am wrong, so I would guess you would be first to be dropped off/last to be picked up. This is just a guess though....