I have nothing up on youtube, but I work with a piano maker who offers the QRS pnomation system as an optional feature with everything we make. the system hardware is a bit of a beast to install, but guy we work with on installation (who used to do PianoDisc system installation) has described the quality of playback on the piano as much higher with the QRS system. I have no real experience with the PianoDisc system though.
I haven’t recorded MIDI off of the QRS system yet and looked at it, but my sense is that the IR sensors they’re using are fairly high-resolution and, when calibrated, are pretty accurate. The weakness of the system is when recording keyboard and pedal, the ability to playback with the same subtlety doesn’t seem possible, as the solenoids can’t reproduce softer playing of the piano.