I've seen the Oratory all my life but never visited it until my friend from BC came into town for a few days and wanted to visit it.
It truly felt like a genuine pilgrimage. Located near the base of Mont-Royal, you have to continuously climb up halfway up the hill and at some points it's pretty steep! Parking isn't free but there's a lot of available spots.... at least on a cloudy day that I visited it. The church is really beautiful and it holds a special place for the local population with "Frere Andre", a local saint reputed to heal the sick and crippled.
The design of the Oratory is pretty on the outside as well as inside and the view from the Oratory towards Montreal is very pretty. There are more beautiful churches in the world but nonetheless visiting is free of cost with many smaller places to visit such as "Frere Andre" old home. I recommend to visit, to attend a service if you're the religious type and most importantly enjoy the sights.