KEF are fairly decent quality speakers. I will never consider buying a speaker with a port in the front, myself, but that's my personal preference.
The KEF Muon is one of the most grand speakers out there, @ about $150k PER SPEAKER, so that "high-end" innovation does translate down to the "lower-grade" speakers.
The fact that they even have such a model boasts how highly regarded they are, and speaks volumes(

) about thier R&D budget.
The 204/2c (3.2ohm minimum)Center and the 1000w 209 Subwoofer are pretty high on my list of "If I had limitless funds I would buy..."