I'm going to be talking more about the markers themselves as the Colour Kits are not widely available in the UK as yet. There are a massive 176 colours in the range, which as far as I know is the highest number of tones available compared to similar pens like Spectrum Noir. Graph'it also promise new colours each year! They uniquely feature two types of grey that are not found in any other marker pallet- pink greys and green greys.
The colours flow juicily and appear vibrant on paper, the wetness meaning you have a longer time to perfect your blends and give that seamless gradient. The pens act identically to all other alcohol markers on paper, spreading rapidly and blending fantastically. It's always a learning curve with alcohol pens, so if you don't have experience I'd recommend buying one or two of them and fine-tuning your technique before diving in with a full set.