A move from Harbeth to... Wilson?

I've always found the Wilsons I've heard over the years to be very forward, "hi-fi" sounding speakers. Conversely, I've found Harbeths to be a very neutral and more accurate presentation of unprocessed vocals and unamplified acoustic instruments (my personal reference point) -- in other words, more natural.  

As such, I'm a little surprised that Harbeth --> Wilson is your flight path. But, speakers are a very personal choice and Wilson certainly has its followers and advocates, so maybe Harbeth was never the best choice for you in the first place. All one can do is listen (ideally in your own home) and then go with the one that best suits you. Forget what impresses anyone else. 

Why don't you move up the Harbeth food chain if you like your current system, but want "more"?  The 40.2 is amazing.

For a room that size there are a lot of options. 
This is of course a very personal thing. I find the Wilsons to be somewhat forward and clinical sounding. The other thing is that the industrial design can be a turnoff for some. I have a lot of wood in my living space and I find the Wilson’s to resemble a mix of school lunchroom garbage can and Transformers robot.

That being said I did hear the Sabrinas played with a very expensive Linn Klimax DSM and Solo amps. Lots of detailed info, but maybe too much depending on your preference?

Your Pass Labs XA30.5 might reduce the hi-fi sound nicely though? I have a XA30.8 with a Linn front end and Spendor D9 speakers and am very happy. 

Move up the Harbeth food chain.  If you really like their sound, moving to Sabrinas may not be the best change.  If you want to try something different, check out the Vienna Acoustics Liszt.

I am a Harbeth 40.2 Anniversary owner and although I have no desire to upgrade, I have always been interested in Wilson's.  Since I have never spent any real time listening to Wilson speakers I really can't say what they sound like in comparison, but the owner of a local audio store, who happens to be blind, once told me that Wilson sounds the best to his ears.  As one might only assume, someone who is blind must know, as they use their eyes to "see" in many ways.  
That said, once I got my 40.2's I really haven't had a single thought to make changes in speakers.  They are so right to my ears, and the path to get to them was long and expensive.  I am sure there are other speakers that I would like as well or more, but would probably have to spend a lot more to achieve this.  The Wilson line generally starts where the Harbeth line ends, even when you buy used.  This has been one major prohibiting factor in even thinking about buying their speakers for me.  I could afford them if I moved some priorities around, but when the Harbeths sound so perfect to me I simply cannot give this option a thought.  
Whatever you do, make sure you can audition them thoroughly before you buy.  And please do share your experiences if you go that route.  I am very curious to know what others learn.