Am using it and think it's great! Setting the physical playback level using a SPL meter was an important part of the deal.
A 1dB stepped attenuator in front of the speakers is unfortunately not rigged up now, but it will come. That'll be the last step to make the system fully K friendly. Can't be bothered to hook up a switched attenuator right now since a Lavry Black is heading this way soon.
The only thing I miss in his paper is some emphasis on oversampled peak metering. I might make illegal samples, but I'll at least know exactly how far the real signal is pushing stuff. Tracking and mixing should never exceed the max of an oversampled peak meter IMO.
BTW: the program doesn't have to have a special "K" feature to use the K system. Any VU and Peak combo can be set to any K level desired.
Andreas
PS:
here's the link if anyone's wondering what this K system is all about