Expensive, but a nice range of colours with good colour saturation. To avoid pilling and bleed-through be careful which type of paper you use. A good quality thick watercolour paper is fine.
The packaging was a bit of a let down - once I opened the packaging and took a pen out, the rest of the pens fall about and bunch up untidily, so I had to take them all out and put them in a pencil case where it is harder to see the range of colours all at once. A flat clear plastic pencil box that keeps them all in place but lets you see them all at once would have been nice.
You can get nice effects if you buy the Tombow dual blender pen as well.