I have owned a lot of different Proac speakers including the 2.5 which you now own.
I upgraded to the D-40r which I still own. The newer Proac speakers are an improvement, especially in the treble. I owned Harbeth Compact 7 (I forget which version) and like @larsman I can assure you they don't rock.
I have not heard the ATC line except at shows so no opinion to share