A good friend of mine went from the Harbeth to to the Kanta, so exactly what you are doing. I have spent time with both in his listening room. The Harbeths were nice and didn't do anything wrong, very pleasant sounding speakers, but not very engaging to my ears. The Kanta 2 is much more dynamic and involving. Even though they are not the speakers I would choose, I would say it's some of the best sound he's had in his room.
Oz
Oz