Greater Than Killer Sudoku: Another extremely hard puzzle

This puzzle, published on Wednesday last week, has an average solve time of over 90 minutes. Which means it is very... very... hard. Simon attempts to explain how to solve it logically... and a little faster.

[bachgammon]

The equation that brought out the 8 on the top row is lovely stuff.

[geardownandlocked]

At 15:19 you put a 6 in the cell but that makes it 18 not 19, it should have been a 7

[saraelizabeth]

I never even understood the concept of this, yet I still watched the entire thing.
Edit: just re-watched the beginning I now understand the concept but I don't think I could solve this puzzle or any like it.

[LazyMonkey]

My brain is melting and I’m only 7 minutes in

[ToTheIceKing]

Sorry to be that guy and point out an error on an old video, but when testing out a 9 on the 19 cage, you put in a 6/7 when it should have been 4/7, which broke the logical ruling out of 9 in that cage

[nestoreleuteriopaivabendo]

Oh, this older software was so powerful! Is this still available?

[coolpapabell]

The 2-9 pair in r1c1 could have been used a second time. It rules out 829 for the size 3 cage in the lower left box, which would get you into the last run a bit sooner.

[carstenkruse]

What is harder to do? A 10/10 killer suduko or 10/10 greater than killer suduko on the dailykillersuduko.com website?