For speakers that are about 38 years old they sound pretty damn good. I did not recalibrate with Audyssey so tried Stereo mode which used the room correction for my Paradigms with subwoofer and then Pure Direct mode to bypass all processing which sounded a lot better of course. With a full range signal (no sub) these speakers have a lot of punch. They are bigger than my Paradigms and the extra cabinet volume and larger woofer produce satisfying bass.
I would describe them as being on the warm side with a rich bottom end. The soft dome tweeter compared to my Paradigms lacks brightness, so at first listen they sounded lacking in the higher frequencies. This diminished with extended listening so I think I needed to retrain my hearing as I am so used to the Paradigms. Over time the KEFs sounded more balanced. The highs were there but a little muted compared to my other speakers. This makes them very easy on the ears though and leads to little ear fatigue. I could listen to these for hours.
I installed an SPL meter app and ran the speakers up to an 87dB average. NRC web site says that's safe for only about two hours of listening. I noticed no degradation in sound and they actually seemed to perform better when I gave them a good dose of power. If my daughter does not use these I would be happy to hang on to them. This would have been a great speaker in the '80s.
I have a pair of Electrovoice Interface 1 Series II speakers from the 80's (like below) that I purchased new. They need new foam surrounds on the woofers and tweeters to get them working. They use EVs Superdome tweeter and employ some of Neville Thiele's research in the design so would make an interesting comparison.