That's a link that's made me look at and feel the keyboard in a whole different way. What he's saying about chords is interesting, but the main thing is about playing higher up the keys - something I've noticed all good piano players do. I've been playing the ends of the keys, especially as I've been working in C major for the last couple of months. But since I saw that video, I've gone back to basics, and started back on scales, (C major, one octave apart, up-and-down four or five octaves, arpeggios, and contrary motion) high up the keys.
It's a difficult adjustment, and I'm much slower and mistake-prone, but it (literally) feels right. For example, on the contrary motion scale, I'm aware that when one hand's playing F, the other's playing G: I'm aware because being higher up the keys I'm more in touch with what key it actually is - the end of the keys in C are, after all, the same - only when you're high up and brushing the sharps and flats, can you get a feeling for each individual key.