We have found that the collaborative benefits far outweigh the distraction factor. Consider the alternative. You stick to that design, even though you learn great lessons as you go. Then you're stuck with software that satisfies requirements from last year, not the current ones. Most of us have done planning in other ways.
Nothing works as well as cards.
It is the simplest thing that could possibly work. True, but we don't stop with the cards. Each card is a commitment to a future conversation between the customer and developers to flesh out the details, when they are needed. Of course, there are other objections to XP in general and to working in a studio specifically. Feel free to learn more about XP at the RoleModel XP Portal .