I’ve been using Harbeth SHL5 speakers in a similar size room to yours since 2007. First the SHL5 model, then the SHL5 Plus model and currently the SHL5 Plus 40th Anniversary edition. Choice of loudspeakers is very much a personal one but I have found nothing to criticise in the sound quality of the SHL5 speakers. Their imaging and ‘natural’ tonal balance allow them to ‘disappear’ when listening. Each successive model I’ve owned brought improvements in transparency and tonal accuracy. If you can find a pair I’d very strongly recommend the latest model, the Anniversary edition (the’ve sold like hot cakes I understand).
Perhaps ‘looks’ may deter you relative to the others on your list - a comparatively wide box - but auditioning each must be paramount. In the UK many of us are fortunate in having dealers sufficiently local that we can audition equipment, including speakers, at home - if you can, do this. I’ve not done any direct comparisons with the other speakers you list (I arrived at Harbeth via Spendor and Audio Physic) but the Kef concentric driver is very good (our son has the LS50). A word of warning (sorry if I’m teaching grandma to suck eggs) the SHL5 Plus may not sound as exciting as the others on your list (its in-room frequency response slopes gently down at high frequencies) but all the musical information is there in a natural balance. With the SHL5 Plus Anniversary edition I’ve found the bass superb in terms of definition and adequate for the type of music I mostly listen to (classical & jazz) - you may find you do not need sub woofers.
To put the sound quality in context I found the improvement in moving to the Anniversary model of the same order as upgrading to Snowmass on the PS Audio DS DAC. Here’s an endorsement from Darren Myers, who uses them as a reference at PS Audio:
Happy listening!