A move from Harbeth to... Wilson?

Going from Harbeth to Wilson is an interesting direction.  I will admit my bias against Wilson speakers.  I have listened to many models over the last several years and the last ones were at RMAF in 2019.  I find them too clinical in the top end and also the integration of the midrange and bass just strikes me as unbalanced.  Perhaps if they are really set up well my opinion would change but I have heard them with top notch solid state and tube electronics.  My test is always violin music and the upper frequencies just drive me out of the room.  I settled on Vienna Acoustics Liszt when I was doing my search.  I guess everyone has different priorities that they value.  

I have had one experience with a Wilson speaker, so I am far from an expert, but I will give you my experience.   I would demo the speaker, preferably in your setup, but if not, then at a dealer.  I would not buy them without listening to them first.

This is my experience with the Wilson Watt Puppy.   The dealer was extremely nice and did a tour of the system the Watt Puppies were connected to, showed me how to adjust the Watch Dog subwoofer, pointed at a huge collection of CD's and said, "You can stay as long as you want, if you have questions, come and get me," and then left the demo room.

A friend and I spent the next two hours listening to the speakers and playing around with different adjustments on the Watch Dog.  There was a seat between the two speakers and if you were in that chair, there was the most three dimensional, accurate, pleasant sound I've ever experienced from a music system.  HOWEVER, if you moved left or right, changed seating height the sound stage became flat and no different than fifty other speakers I've heard.

The Watt Puppy speakers were extremely accurate, but also, extremely directional with a very, very small soundstage.  Whether that's the case with the Wilson speakers you're considering is unknown, but you should listen to them very carefully before buying them.

OP: check out the room size here:
https://www.whatsbestforum.com/threads/harbeth-monitor-40-2.25222/

your Harbeth’s have that Rogers, Spendor, Stirling Broadcast (Proac ATC?) BBC monitor lineage and dna.
dare I say an apples and oranges comparison discussion in regards to Wilson?
I would move up to the big box Harbeth 40 as others have suggested and maybe treat yourself to an additional upgrade elsewhere in your system.
you will be after all... saving several thousand delore’s on that automotive paint finish🤗

Haven't heard the Sabrinas, but I'm a bit cautious as they are the latest generation of what started as the Watt/Puppies none of which ever captivated me. Problem is that anything above that in the Wilson line escalated price very significantly. Best to do some auditioning yourself ad think about it.

(FWIW I have loved several models of larger Wilsons and have a pair of Maxx 2 in one of my systems - the Alexx are the modern speaker in that niche today).