Your Michelia is very beautiful! I agree somewhat, I think Michelia alba is fragrant but it is mild by (our Eastern) standards unlike jasmine or motia. I also noticed that we need the right amount of humidity and heat to make the surrounding air fragrant. I really want to see champaca one day.
This is the picture of my grafted magnolia champaca i shot in July 2015. Not a sharp picture but will do.
Also find the current state of plant on my rooftop as of today. It attracted some pests so had to spray with some insecticide. I am keeping it in its 14 inches pot after all it is a slow growing and shallow rooted plant