The idea that “vanity cards,” more commonly called custom cards, are bad for magic because spectators will think they are trick cards is a myth that got perpetuated by a very well reasoned essay written by Jamy Ian Swiss several years ago. What people forget, or never knew because they never read the actual essay, is that he was referring specifically to “Black decks,” that at the time were the most common custom cards on the market. The modern custom card market has a relatively small number of “Black Decks,” and so the original basis for this myth has lost a lot of its steam. I haven’t actually performed with a Bicycle deck in over seven years and yet in that time the one and only time my deck ever aroused suspicion was one of the few times I used a Black deck!(Which is pretty much limited to Halloween these days;)
The people who keep this myth alive miss a key point. We do not refer to our spectators as laymen for no reason! They really DON’T know what a trick deck looks like! They DON’T know that a Bicycle deck is the most commonly gaffed deck on the market. In fact…most would not even notice the difference between a “Red Backed Bike” and an Ace Fulton Casino Deck. The key thing to consider is the white border. As long as your deck has that white border then your spectators will be unlikely to assume anything suspicious about your deck. The best defense, of course, is reality. There are just not a lot of gimmicks available for custom decks. So at anytime, if someone does seem suspicious, you are free to toss your spectator your deck, let them shuffle it to their hearts content, and go right into Oz Pearlman’s “Clutch!” http://www.penguinmagic.com/p/1875
Those are the reasons not to worry about Custom decks…but what are the advantages? Other than being a collector or liking a pretty new design, not much. That is, unless you are really concerned with the quality of that card. For most magicians the quality of the average Bicycle 808 will be just fine. For other magicians you might find high quality cards will perform difficult sleights or flourishes better and there are many custom cards, though not all, that tend to last longer. The details of which custom cards are worth the extra money and which custom cards are a waste of money, is beyond the scope of this question but trying out the feel of different stocks and finishes is part of the fun of discovering custom cards!
To learn more check out the tag for “Premium Decks.” http://www.penguinmagic.com/tricks/tagged/premium-deck