Has anyone made use of the Draft Cards and drafting rules? What do people think of them in general?

Tried a draft with the core set the second evening that I played. I thought it was pretty fun. Trying to get my local store to schedule a draft event sometime soon. I do wander if any rules tweaks will be necessary to include cards from battle packs or semi-constructed decks for drafting.

Battle Packs no, semi-constructed decks probably... the draft rules are intended for the CS cards and the ratios present. When you take constructed decks and apply draft rules to them it really changes the way things are intended to work. The more tightly constructed a deck prior to draft the weirder it is going to be.