Just watched and I know he's more of a Korg OS guy, but that being said...
The one dislike that has me concerned is the screen angle. (I'm awaiting delivery of a SX-900) I don't know why Yamaha didn't angle the screen, or better yet, a tilt screen would have been nice. Does anyone agree with his "washed out" view opinion? Is it that bad you can't naturally see the bottom of the display?
Also he may or may not be correct about a T-4, or a T-5 being better, but a USED T-5 is at least $1,000 more than a new SX-900
So for me, most of his dislikes are minor issues, while his likes are major upgrades. His dislikes should not damper your decision to purchase the SX-900. They are just opinions after all. Nothing is perfect.
I recently bought a new TV, and drove myself crazy listening to all the likes and dislikes. Finally just made a decision to buy one, after realizing again, that nothing is perfect.
Nice video though, thanks for the heads up Ton