speaker upgrade fever

I actually have KEF Reference 1 and really enjoy them but will be moving to Jean Marie Reynaud. There is a set of Grand Opera for sale locally and I'd own them right now but they are just too big for my space. They are like no other speaker I've either seen or heard. JMR has a particular sound and lushness I've just not experienced with any other brand and I've owned Audio Note, Sonus Faber, Revel & Focal. Anyway, I'm going to get the more manageable Voce Grand; mind is made up. I demoed them in Montreal last fall and although not as big a sound as the Opera, they are mighty good, Jazz & simple uncomplicated music being where they truly excel. Tax return can't come fast enough, lol. 

I am unfamiliar with the Mimas pairing, but have a pair of Vandersteen Treo CTs and they are incredibly musical.

Harbeth is a great speaker, never heard the Pulsar. Just be careful the Harbeth's IMO don't want to be pushed too hard. I heard the basket clink a couple times.

Devore makes great speakers too but get out and listen to them no substitute for that.

Harbeth and Joseph Audio speakers share some similarities, but are also very different in some ways.

They both do imaging and soundstage very well and are fairly neutral.  Harbeths are less detailed.  Your KEF Ref 1 speakers have more detail than any Harbeth I've owned (I have not had the 30.1, which I think is what you meant you are considering).  The Kefs are also a little bit warmer, Harbeths (depending on the model) can get a little hot at the top end when pushed.

The Joseph Audio speakers will be more detailed than the KEFs or Harbeths, and will have better imaging, to the point where it is almost clinical, as in the instruments and vocals are very defined in space.  I really like this, but there's the possibility of being drawn into the presentation versus being drawn into the music, which is where I think the Harbeths excel.  

I have listened extensively to a friend's system with the JA Pulsar Graphenes and would take those over KEF Referency 1 or any Harbeth speaker I've heard.  I have owned Harbeth Super HL5 Plus, Compact 7, and P3ESR.  I loved them all, with the last two being my favorites.  The same friend that has the JA Pulsar Graphenes also had the Harbeth 40.2.  I remember when he told me had moved on from those, I thought he was nuts.  Until I heard the JA Pulsar Graphenes in his system.

I'm an ATC active owner and Focals. I run my atc w Tubes. For me it's tbe perfect balance of detail and musicality. The focal paired w Naim is also unique but the speakers can be interpreted as bright. So I mention my setup for refrence... however if I was interested in moving slightly away from detail to something forgiving and evwn more musicality... Sonus Fabre are going to be my go to. They are gorgeous.... to be honest if I was starting from scratch and trying to decider my setup or SF I'd be torn... I'm already completely committed w Rel subs too and I love my system so I'm not considering anything else. But SF r very impressive for my taste and slightly different flavor. Plus they are gorgeous looking speakers especially in tower. Just a heads up... in tower you sacrifice imaging. I've heard SF bookshelves and they are loud and deep w bass very impressive, I even asked if they had a sub hooked up in which they didn't. Never heard speaker imagine like SF. And if you wanted to add more bass you could c9nder a pair of Rels and maybe have everything you wanted in that setup. 

One last set of advise, if your have tubes I highly recommend NOS tubes. I run 1943 Ken-rads amd I found these to be the best tube nee or old. Deepest bass of all tunes new or old and rich thick mids. And didn't loose any details in tbe highs. Thought I'd mention that. Best of luck