I got the trial version and threw what I found into the video attached.

A couple of findings:

• The different effects and their parameters should be learned like audio FX if you want to effectively apply them. Not a surprise, but there are quite a few so there is a hurdle to overcome.
• The FX are not demanding on the CPU at all. Which means videosync could qualify to be used on the playback computer in the backing track file. Although running M4L devices on your live playback is risky.
• Videosync FX can be modulated like all other Ableton FX parameters; LFO, envelope follower and modulation/automation can be used with them which is obviously super duper freaky awesome for real-time input dependant manipulation.
• There are even "instruments" that read Midi and manipulate the video depending on Midi input.
• As my test video shows, different video sources can be used. This includes live feed from a webcam or even an iPhone.
• Question your taste. It's easy to overdo things. I have a tendency to overdo. After all, "more is more!"

I won't buy it just yet. But there's a very good chance this will become part of our live setup.