As a KEF dealer, I am a bit biased, I will tell you in the past I have sold Dynaudio and they are very fine speakers.
They do tend to do different things and appeal to different listeners:
The Dynaudio tweeter is extended but quite smooth, lovely midrange, the Dynaudio's tend to need a lot of power before they sound dynamic and have good tight bass but are tuned a bit dry in the bass.
The KEF 207.2 when set up correctly are totally transparent, and have a wider, and more precise sound stage due to KEF point source dual concentric design.
Although the KEF's are not rated on paper that low they go to the low 20s and can be played with small tube amplifiers and will play quite loud on even 20 to 30 tube watts.
I tend to show them with powerful solid state to show how loud effortlessly they can play. We use a number of big amplifiers all 400 watts either Parasound JC 1, Electrocompaniet AW 400 or Chord 650 mono blocks which are also 400 watts, and the 207.2 just play louder and louder and louder. They are rated to be able to output 117db and I can tell you with enough clean power they sound like you are in front of a real band.
The only problem with KEF is they have too many poor dealers that do not know how to set these speakers up correctly, the 207.2 have a remarkable titanium tweeter which goes up to 60K they are very revealing, any brightness in the system they can sound harsh, with the wrong amps or placement they don't go that low, if you work with them you will have a full range transducer which in my opinion can do battle quite easily with Magico or Wilson and come out $8k cheaper is a very good thing.