Hi Donny,
Thank you for posting this. I've been following his videos for a while now and I really like how he presents them.
I share some of his sentiments, its very true that the previous models of the S970/S975 do sound just as good in a lot of area's, I know as I still have my S975 and I've been comparing them. It's still a worthy upgrade though.
One thing that nobody has been able to explain yet are the drums, what exactly are they if they are not Genos drums. He quickly skipped past that topic because perhaps he didn't quite know himself. 
Other things that's not been mentioned is that it appears the SX900 doesn't seem to have Video Out which is surprising since it can be useful hooking it up to a monitor and most previous models had it.
Still early days and lots to explore though, I am sure the SX900 will open up more.