Interesting findings, Dan.
You may have seen I recently posted about my two systems - Naim SN and Harbeth p3 with mac mini, vs my new ADM9T. Still enjoying both systems, and it's easy to spot the differences. Naim / Harbeth is a full bodied, warm sound with a sweet treble whilst the 9T have a cleaner, faster sound, perhaps more versatile across genres too.
It's hard to say which I prefer, but the 9T are 25 percent of the price. The big plus for the 9t is the clearer definition between elements, although some listeners don't like this effect, and prefer a more homogenous sound. Also, the 9t have great imaging but the harbeth have a lovely smooth sound. I swap between them now and then and enjoy the differences.
The Naim and Harbeth are lovely products with great build quality and a joy to use, but the 9t keep things very simple and hassle/upgrade free. They are not as well built though, but you wouldn't expect them to be for the price.
I would live to try some ATCscm50 or 100 actives one day, when I have a bigger living space.
More of a design thing, but the adm40s are not for me. Apart from being too big in my room, I'm not keen on the digital readout on the front, nor the extended plinth. Of course this is purely subjective, many will love these features and likewise, many think harbeths are ugly... Whereas I think it's hard to find more seductive looking speakers! The 9t are fairly non descript (like proac) when they have grilles on, so they suit my tastes just fine.