Functionally it's good - adapts to both light and dark background, adapts to both 256 and truecolor terminals. I think I miss some of the color even if bright color in light background themes is often detrimental. Only real dislike is the too gray tinted background. Should be more towards white for light background, to be more neutral.
you might want to try linking @variable to Identifier, i think the original author decided to keep @variable unhighlighted to keep the color diff between having `termguicolors` on/off to a minimum (Identifier assumes `termguicolors` is enabled, but for default colorscheme it's likely not always the case).