Something I really really like about the Artifact coins is that there is zero branding on them and they look really stunning. I dig the quotes too. I suppose they make any magician look smart.
Something that may be arguable is whether the coins are a bit too heavy or not. And the sizes are perfect for me but if you have smaller hands you may never be able to use the full dollar sized ones since those are really big. I guess they should have made a smaller version too, rather than just extra-large (dollar size) and medium (half dollar size).
What I really don't like is that the silver coins feel rough there where the copper ones feel slippery and the silver ones are way less shiny than the copper ones. In very bright color change situations this latter aspect would be a plus because the contrast would be bigger, but in average or low light situations (which are far more common) this is a really bad thing, especially when wearing dark clothes because the silver coins would be amazingly difficult if not impossible to see.
That said, nothing beats your average currency coins. Remember that magic is about making the impossible happen with props your spectators are familiar with.