CS6 can't import MP4's (& other popular video formats) which is a major limitation. CS6 & earlier.... is "Frame animation" only. "CS6 Extended" & later.... is the first version to have the "video timeline." Making animated stuff with only the Frame animation is incredibly slow to do thingz one frame at a time & it comes out choppy. With the video timeline function, you can do a lot of "maneuvers" in which the program makes it smooth from one point to the other. For example... set point A... then set point B & the program fills in the middle & makes it smooth like video instead of like a choppy "early Southpark" style frame animation. This works in regard to moving things on the screen, making them different sized, or rotating them. In Rotating or resizing in "Frame animation", you actually have to make a different duplicate for each rotation or resizing... but with the video timeline, the software fills in the gaps without having to make all those duplicates. I butted right up to this limitation by not having the extended version. I now am stoked to have a newer version & am currently in rehab trying to kick old habits.