With so many friction hitch options, I've had trouble remembering any. That traditional method is different enough from all the others, it may be easier to remember.
I've tied this both ways and of course the only noticeable difference is which side of the hitch (let's just say front vs back) the legs go. Both work fine but I'd like to know what are your thoughts on that? Is one way more correct than the other, in regards to which side you direct the legs together to clip in?
I don't recall what I used in the video, but most prusiks used for the VT are between 28 and 30" long (71-76 cm). The best length varies for different rope diameters. You will need to experiment a bit to see which length works best for your particular rope. It your prusik is a bit long you can often make it work by adding an extra braid around the rope.