Current or Previous Harbeth Owners…

NOPE!
 Only the Sonus Faber Toy Towers I had even come close to the performance of my current M30.2Xd's & even those were not quite as transparent through the midrange...

I previously owned 40.1's and 40.2 Anniversaries.. preferred 40.1's fwiw.

I found YG Carmels were more enjoyable/musical than M30.2s in a medium sized room powered by Luxman L-590 AXii. Not by much though, and they’re 3 x more expensive. Harbeths are hard to beat, depending on what you listen to. In the same room I preferred M40.2 to Magico A3 with Luxman separates. In my current room I prefer Focal Kantas. Not as natural on voices but all around better soundstaging, bass and highs; more linear. Musical enough, and easier to pair with amplification. I haven’t had the M40s though in my current room, only the M30s. I’m sure if I had the right amplification and set up there’s a good chance I might prefer the M40s to the Kantas.

If you’re thinking about M40s, just make sure your room is big enough.  My original room was 14 x 21 feet, and while the 40s sounded great in there, ultimately they were just too big, too much bass.  I went from the 40s to the 30s in that room.