Got the filters from https://www.homeaudiofidelity.com/ and they provide a very noticeable jump in sound quality compared to my old REW + PEQ room correction. Quieter background, more dynamic and wider stereo imaging. From a sound quality perspective, its the best money I have spent.
They also give a very big boost in volume, without any clipping (compared to using REW + PEQ). My current Roon volume is at 20, and that’s about the same volume level as 40 was for the old filters, and I have tried to provoke it with some tunes I know can easily cause clipping, but so far no blinking red light in Roon.
All in all, a very big “thumbs up” for Thierry, I don’t know how he did it. but whatever it was it worked like magic 
PS: as far as I can tell, this room correction is better than Dirac, although i don’t have it available for a proper A-B test.