The Mayan Red Pigment is an absolutely brilliant color. I mixed it with walnut oil to paint with. It is also border line warm/cool depending on the other colors around it. It will definitely brighten any palette.
I've been painting with traditional acrylics and oils for years, but really dislike the resulting environmental and health impacts. So a few months ago I decided to try these. I've now done several pieces using Natural Earth paints and medium exclusively, and in thrilled with the process, vibrancy, and finished results. They are very fast drying (I had been using open acrylics by Golden) but very workable, especially adding medium as needed. I'll probably have to try some of the other product now!