The more complex the interface becomes, the weaker the card maker becomes in my opinionunless it offers some wild power to go with it
Commercially, this looks like a high-interest set rather than a quiet collector release
Were already seeing Zendikar Rising experiment with using different card types as the front side of these, which will affect deck-building and combo options across various formats (the front side determines how you can search for or target these cards when they arent in play)
It may seem ridiculous, and while I don't agree with the practice of selling cards before you actually have them, Gengar is a very popular purple rascal
However, there are some exceptions to this rule, as a few cards can apply a status effect while they are on the bench, and the best card that fulfills this role in a deck is Brute Bonnet
Where is the difficulty