My personal experience with AK pencils has been meh. I used them to add oil stains for a UN T-72, but they were too brittle (cracked quite easily). The biggest issue was that no matter how much I soaked them in water, they never deposited much pigment. Using them was just not really that worthwhile considering that enamel paints exist.
But to each their own! Perhaps you’ll love them, we all have wildly different experiences.