Spendor D7 vs. Harbeth Super HL5+

once again, try the grilles off of your harbeths if you have not.  totally different sound, dynamics, top end and transparency open up quite well.

I heard D9 on Montreal Audio Fest with Chord amplifiers.
The sound was horrible, scratchy, bright, unmusical.
People entered into this room and nobody can stay there more than 2 minutes!!!
But I am curious - was it because amplifier or it is a normal sound of these speakers?

Your description is as far from the reality of the D9s in my system as possible.  They are extremely musical with beautiful clarity and detail.  Setup and proper positioning are paramount to their performance as is true for any speaker with their capability. I can imagine the best placement in a hotel room at a show could be sub-optimal as I have experienced at many shows with other highly reviewed speakers and systems.

That's funny, you may have been in the same room with Art Dudley :)

Checkout:  https://www.stereophile.com/content/arts-saturday-morning-show

He seemed to like the sound.

The system overall had an impressive combination of clarity and beauty, openness and substance: I could have stayed there all day.

Again, we all hear differently, and like what we like...

In the D7 vs. Classic 100 comparison (remember: made by the same company), it wasn't just the D7's tweeter that I didn't like, it was the whole upper/mid range that sounded undernourished and constrained and unnatural by comparison to the '100, plus overall there was considerably less impact compared to the wave launch offered by the '100. It's a real pity this model isn't more widely auditionable in the U.S.  But people (spouses) want narrow speakers for the décor, and Spendor now actually vaunts this narrowness in its print ads.  A sad thing.