Canada 2021 (i.e. the ACU Codemasters version) might look prettier, but the Montreal track by Terra21 (Automobilista conversion) is without a doubt the much more accurate track! Drive both versions, compare both to real onboard videos (speed, steering input, pause at tight sections) and then you will notice how hilariously bad and inaccurate the Codemasters track is (but that's nothing new unfortunately).
You can find the biggest differences from turns 3 to 9 (basically the whole back straight section) and in the final chicane (13 and 14).
Terra's version just feels right, the chicanes are tight and the track itself is pretty narrow (just like in real life).
The Codemasters version is too wide in general and this also means that the corners/chicanes are too wide as well.
Track too wide => corners aren't tight enough => you need to brake and steer less compared to real ife => unrealistic speeds in certain corners/chicanes.
I was talking to
@Pyyer about this in September 2021 and he completely agreed with me, the Terra21 version is the better and more accurate track.
I really, really hope that Pyyer is using the Terra version as the base for his next extension update.
This is the perfect opportunity to finally get rid of another inaccurate Codemasters track!
Another texture update won't make the ACU version any more accurate.
Using the time to visually improve the Automobilista / Terra21 version would be a much better choice.
I think the majority of the community isn't even aware that there's a much better Montreal version out there!