I played today a 23.97fps file in 50Hz mode (on my 50/60Hz only display) and it was much smoother than the usual 60Hz mode playback. I assume VideoClock speeds up to achieve this. What I remember about ReClock is that when it did this, the audio quality suffered a lot (stereo/multichannel image degradation etc.). I wonder if VideoClock manages to solve this problem, or if the quality loss is inevitable in this case.