Buy Teff Whole or Teff Flour?

http://www.traditional-foods.com/profiles/teff/

If you plan to use teff in baking, what is best for optimum freshness: Buying whole teff and grinding it at home or buying teff flour? Usually we recommend buying the whole kernel and grinding it for best freshness and cost savings, but teff is difficult to grind in a home grain grinder. We recommend buying teff flour for baking.