Regarding the Harbeth vocal magic...
You may find you actually prefer the Joseph speakers, even in that regard.
It was actually hearing vocals on some Joseph speakers that got me interested!
I’m always comparing the sound of real voices to reproduced. It’s a habit. So when I audition speakers, or go to audio shows, there’s usually people talking.
When I’m listening to one of the inevitable demos with vocal tracks, I close my eyes and compare the sound to real voices I can hear talking, and it always reveals how artifical the voice is coming through the speakers. Voices sound "off" tonally, timbrally, compared to the organic timbre and tonal color of real human voices.
It’s actually been the Harbeth speakers that have tended to "pass" this test best at some shows.
However I was at one show (Montreal I think) and had entered the Joseph Audio room, with Jeff Joseph there (IIRC) and the Pearl speakers. There was a vocal acapella track playing. It completely startled me. It wasn’t so much that the voices were so clear and vivid. Vivid sound was typical in such speaker demos. Rather it was the pure realism and accuracy, the naturalness of the timbre of the voices. It just sounded bang on to the warm, organic timbre of real voices. It passed the "close my eyes test compare with real voices" with flying colors.
I was so blown away it led me to seek out Joseph Speakers at a local dealer, and again I heard a similar mesmerizing quality from the Pulsars, then the Perspectives. And again I was amazed by vocals. The Joseph speakers are so pure of grain and revealing of timbre that I found they actually made female voices sound more distinctly "female," male more distinctly "male." It’s very hard to describe what I’m talking about, but female recorded voices tend to be extra sibilant, and the sibilance can exaggerate any hash a speaker might have in that region, giving a slightly obscuring chalky coloration. The Joseph speakers sort of slightly wipe away the grain so even if it’s a sibilant recording, the subtle timbre of the vocalist is revealed with more purity. In that way female vocals sounded less artificial and more like...well...a female singing :-)
Of course, this is how it sounds to my ears. YMMV.
But again, on the flip side, the vocal presentation on the Joseph speakers is not the "BBC vocals" you get from Spendors or Harbeth. With the Harbeth theres that slightly added richness, palpability and density for voices. I found with the Harbeths (like my Spendor S3/5s which I still own) that there was always a human being singing in the mix, even if the recording wasn’t the most natural. So even electronica or pop with processed vocals, it was still human sounding in the sense of having that organic softness and body.
The Joseph speakers, in that sense, will be more recording dependent. An artificial recording will sound artificial, but very timbrally clear. A vocal recording with some richness will sound rich. Harbeth are more consistent from recording to recording in making vocals sound human in certain aspects.
So for vocals, it really depends on what the individual keys in on, because the JA and Harbeth speakers each capture some aspect of the real thing better than the other. The JA revealing more purity of timbre, the Harbeth adding a very life-like richness to vocals.
If you hear the Perspectives I’d be very curious as to whether your impressions are similar to mine. You never know.