The RÉSO is pretty nice, its main part connects between 6 subway stations under downtown: Lucien L'Allier, Bonaventure (with its bus and railway station), Square-Victoria, Place d'Armes, McGill and Peel. It connects directly to shopping malls, to "Centre Bell" arena and to multiple office buildings. It would be perfect to extend it and connect through Saint-Laurent station to Berri-UQÀM, the biggest station with 3 lines and tunnels to multiple university buildings.