Le Circuit is a great track! As a young man, I raced there often when club racing was alive and well at Tremblant. It is a fast track with a number of challenges.
Over the years, the track fell into disrepair and had ownership changes. A while back, a new owner made major improvements - both to the track and the infrastructure.
But - (there's always a 'but' - lol!), access by clubs for track days has been very limited, costly and often subject to last minute cancellations - if the owner decides to hold a 'private' event on a whim.
Here's an old write up from a few years ago: NR's 300C Devastates Competition at the Track - Almost!
As to comparing it with Calabogie, (CMP) here's my take:
Quality of track surface - CMP best
Safety & Run offs - about the same
Track Personnel - CMP excels
Average lap speeds - Le Circuit faster
Technical Challenges - CMP better (better learning environment for every type of corner and elevation change)
Facilities for drivers and vehicles - CMP is better
Attitude of track owners towards novices and learners - CMP is very positive & helpful
Amount of track activity per season - CMP way ahead
Hope this helps!