I owned the Harbeth C7ES3 for years and have lots of listening time on the MoFi 8s. 10s and 888s.
The MoFis have good attack and better bass. However to my ears they are not refined and the midrange has no magic or bloom.
The Harbeths are super refined and smooth and have excellent midrange warmth and detail. Listen with the grilles off.
When you are used to the refinement and forgiving nature of speakers like Harbeth and Spendor (owned two of each) the lack of refinement that the MoFis present is a deal breaker for my ears.