I’ve owned the Harbeth C7 and the M30.1. IMO, they both sounded nice but boxy. My favorite Harbeth is the P3ESR. They really do a disappearing act when in a smaller room like yours. You can get a pair at the fraction of the cost of those others that you are looking at. If they don’t work out they are very easy to sell. Here is a video of a guy that agrees with my opinion about the P3ESR!
https://www.youtube.com/watch?v=mqFIaiPT_kY
And another!
https://www.bing.com/videos/search?q=harbeth+p3esr+review&view=detail&mid=5D7EB69CCEBBAAE793...
https://www.youtube.com/watch?v=mqFIaiPT_kY
And another!
https://www.bing.com/videos/search?q=harbeth+p3esr+review&view=detail&mid=5D7EB69CCEBBAAE793...