Judging Vivid Yellow Diamonds requires a good eye. Many people qualify - I'd even say most people.
The color is not subtle, so you can look at it and decide if you love it.
To me, what's desirable in a Vivid Yellow is the type of color you see in this stone. Pure, bright yellow.
Great cut - the stone sparkles from every possible place it might.
There are a few carbon specks buried within - the color and cut obscure them - so the diamond is eye clean.