The humid tire is especially for damp tracks, it's a very soft tire (20-25 shore) which only works in a very small window.
If it is too wet you will only spin out, if it is too dry you wear them out within 10 laps.
So I never use these kind of tires, a normal electro slick tire is much better in these circumstances.
The Capricorn Hardlight tire is just a normal tire, but with a stiffer and lighter rim compared to normal tires.
It's very good, you will notice a big improvement in fast direction changes, the car responds faster and just grips.
I only order from Capricorn directly because their service is top notch, shipping is very fast.
In the US Capricorn is being distributed by Team Epic:
Maybe someone from the US can chime in on any resellers in the US.