Definitely Nissan 1.5L CVT is extreamly efficient with my experience.
As for Civic 1.5T CVT with my experience it was little fun for a CVT trans when Traction control is off. I was able to get little wheel spin. However couple of time i felt something like a slip when i brake torque to get some faster acceleration. I don't know if the 'brake torque' is the correct term I was pressing brake pedal and gas at the same time to get higher revs before i let go. This is when I felt the slip on a new car. Again I don't know if its a slip on transmission or is it from brakes.