As I've mentioned, Harbeth are one of my favorite speaker brands. I've heard the whole line up a few times and owned the SuperHL5plus. I could certainly live with Harbeths as my speakers.
If I could fault them on anything, the Harbeths do lack some of the punch and solidity I find in some speakers (especially my Thiel 2.7s).
The Harbeths do have a clear, open sound. And one of the attributes I love is the density - voices etc have a corporeal, filled out sound with body. So they are rich and have a sense of density in that sense.
But the overall sound, compared to my Thiels for instance, is a little bit "puffy," sort of like I can sense the box a bit, and drums, bass guitars etc don't have quite the "right there" solid slam and presence. The Thiels (and some other speakers) also sound a bit more tidy and clean, more precise.
I still think Harbeth have a particularly great sense of balance to the sound, and I enjoy all genres on the Harbeths. But if I had to pick nits, those would be mine.