I did not feel in the slightest bit impaired. I am a regular user of cannabis and smoking a joint a couple of hours before driving which would not have affected the standard of my driving.
It does not matter whether or not you felt impaired or whether or not the quality of your driving was affected. The only issue is whether or not you were over the legal limit at the time you’re driving.
Arguing that you are a regular user of cannabis and that it does not affect your ability to drive is a double edged sword.
It’s likely to make the court think that you regularly drive whilst under the influence of cannabis which may make the court give you a heavier sentence or suggest that you don’t respect the law in general.