Video for motion analysis has always seemed a bit redundant to me. The fact is that videos provide only 2-dimensional data, regardless if there are 2 (Specialized!), 3, 4… Most cameras are only fast enough for < 80% accuracy, and two millimeters error using “line-drawing” tools can alter function ten-degrees or more.
Dartfish and Quintic software are different, because they provide kinematic functions like trajectory and digitization.
I recently purchased the Quintic Biomechanics/Coaching Software, in route to getting the Biomechanics 9.03. Hopefully, we can get more US bike-fitters using this phenomenal product.
Best utility is for demonstrating postural considerations and gross positioning issues.