This is the cheapest option from the airport. Long line at the airport bus station to downtown. A bit of confusion since there were 2 lines. One bus goes to the metro station outside of downtown and the other bus to downtown. You can take either since once you get on the metro it also takes you downtown. The bus was air-conditioned so that was nice. However once the luggage racks are full on the bus they won't allow anymore passengers. Liability issues I guess.
Coming back to the airport was only okay. Luckily we didn't take the metro to station Lionel-Groulx. The driver wouldn't take anymore passengers since the luggage racks were full. Very annoying since the bus wasn't full. It was good that we got on at Berri-Uqam stop. 3 stops later the bus driver refused anymore passengers that had luggage. And the bus wasn't air conditioned.