Static vs Dynamic: What doesn't come out in the discussion is would you choose a static option over the dynamic one if you had a choice? I think for the expert map reader (I'm thinking of a biologist tracking animal movement as an example) a static map has a number of advantages, it can be scanned quickly to find the point/time you are interested in and values of velocity are easy to read off. By comparison, an animation must be played to get to the point you want to view. As it can be printed it's also very portable.
For the bloke on the street, I think the dynamic version has most advantages: understanding the static version requires interpretation, the animation is instantly recognisable. Also, animations instantly attract the attention which is important for the public but not necessary for the expert.