Depends.
I like using the "specialty" cards ie. vipers, ghost, tiger ect. but only for cardistry with a little magic thrown in. If I'm planning to go out to perform magic just a pack of bikes. There is something to be said for just using regular bikes when doing magic. One of the first thing people will accuse you of when using specialty decks is that it was a trick deck. Which in my opinion takes away from the effect. We are supposed to be doing extraordinary things with ordinary objects. Why do you think the gimmick for distortion comes in either red or blue bike backs.If their default reasoning for the effect is that is was a trick deck where is the magic? It then becomes the cards doing something incredible, not you. I've actually come back from doing magic at a party(using specialty decks) and had people say "Hey, do that trick with the trick deck!" I don't know about you but I'd rather be remembered for the magic I'm doing, not the cards I'm holding. Lets be honest guys. The only reason to use specialty decks is that "we" think it looks cool.