When you look at the picture, you think they're about 8 feet tall. Actually they're 51" tall. That's 4'3" which is not really overbearing at all. Basically mini-towers that can play distortion and compression free to around 105 db down to 30 hz with the room gain.
I'm reading a lot in here about the bass shelf, but as someone who has Dirac and two 12" subwoofers, I can tell you that generates some hellacious 15 db+ standing wave peaks in a real room. I use Dirac to saw them down to size, but I can't help but think Kef might be smart by letting the room do the work for the speaker down there, given that a lot of these flat to 20 hz in an anechoic room big boys just create peaks have to be attenuated with EQ and or DSP anyway. So why not just take advantage of that to make something with the smaller form factor and the cheaper price and put the money into the finishes and driver quality, thereby getting the same or better sound quality in normal listening rooms? Seems like that's what Kef has done here.