Moon-and-Star: Fancy dice are great .... in theory. In practice, it's a bit hit-and-miss. The mage dice OP linked, I personally think look neat but wouldn't take chances playing with them; on the other hand, I bought a box of fancy Call of Cthulhu dice recently (these ones, to be precise) and despite their design, they work perfectly well when playing, they're easily legible in ok light (if you're playing in darkness, well, there is a glow-in-the-dark version of them :D).

Unless I could test these mage dice in a shop and see how they work, I wouldn't buy them. Supposedly they're designed to give the same rolls as their more conventional siblings, but if you have enough stuff on your table (like snacks, drinks, books, etc) they're probably a lot more likely to simply roll off and disappear beneath a sofa. Happens frequently enough with normal dice, and losing one of these expensive things to that? Bitter.