I've got two, a peppermint one, and a butter rum or some such like that.. I honestly can't tell much difference between it and other acrylics, or acrylic polyester blends that are popular now for gun grips,knife scales, and pen turning. Kirinite is another one with a name, same basic material IMO, just a different brand name I'd bet.
Its definitely harder than delrin, doesn't mark anywhere near as easy.
Its not, IMO, like the mentioned counter top materials though, Corleon, and Corian. Those are denser and heavier, and they don't get as glassy smooth. The Corelon on my two knives are polished like glass. From my research, all are acrylic resin based, just different things added for structure/ color/ opacity.
Also, not that it matters fir form or function, but some folks like to know such things; the Corelon handles aren't put on by Case. At least they haven't been for past runs up until a few years ago. Not 100% sure about now. There isn't a quality difference, can't tell they're not factory done.
Case was building the knives sans covers, and they're sent out to a contractor that does limited numbered runs. They're not pinned on and shaped, but they're not exactly epoxied on either; The stuff is basically cast in place on the knife, then final finishing is done. Have read about modders trying to get the stuff off, you basically have to grind or blow torch it off... Its not going anywhere verry easily.