I enjoyed these videos immensely and have watched each a couple times. Like many others, I have been watching YouTube videos to try to compare these two synthesizers, and, also like others, I don't have a nearby store that has both to compare in person. (Where is such a store? It's difficult on most sites to see what DSI they actually have in stock.) Your videos are valuable for that reason.
On another level, I greatly enjoyed watching someone who really understands both synthesizer programming and these two keyboards in particular, easily navigating the parameters to vary sounds. I'm new to the Prophet '08, and it's educational to watch someone farther along the learning curve. For example, while I've read the manual's description of programming the sequencer and have heard many sequences online, I'm not aware of another video that demonstrates how to set up a sequence. I would have enjoyed watching the few minutes between videos 4 and 5, when you were adding the modulations.