I agree with JButterfield in a sense here. Coins can be simple, elegant, and absolutely mindblowing when handled by a well practiced magician. But it goes south without practice and without creativity.
Cards can twist the way you think and challenge the spectator's perception. But when card effects are performed without practice and preparation, they can be cringe-worthy to watch as well.
Both have strengths and both have weaknesses. In the end, I would like to think that they pretty much balance each other out. It just depends on which the magician likes to perform better, and if he or she likes both, all the power to them. Like anything, both will create amazing effects and experiences for the audience, it all depends on how they are used, and more importantly how WELL they are used.
I hope this helps straighten some things out or at least give others a good perspective on magic as a whole, because that is how it is with all areas of magic.
-emagician