cookybiscuit :
It's not something that can be demonstrated through a Youtube video. It basically gives LCD's CRT properties, theres no image retention so theres no perceivable blur at all, downside is your colours look even crappier than a normal TN display.
There is no inherent reason that Lightboost has to cause poor colors, but the current Lightboost monitors do. The new G-sync monitors are supposed to fix, or at least greatly improve that problem. At least that is what has been said. Lightboost was meant for 3D gaming, it just turned out it was used in 2D, which might account for the poor colors, as in 3D, it is used with glasses with tinting.
OP: Lightboost has nothing to do with tearing. V-sync fixes tearing. Motion blur on a video comes in two fold. Your monitors motion blur is still in effect, and the camera videoing the display also causes motion blur. Youtube videos are also at 30 FPS.
This is something you must see in person to know how it works.