Thought it was kind of cool, I played 1 round got my pack and moved on. I'll play a few more games when I have some more time. I like the discover mechanic in general as it brings in some choice with the rng.
I prefer the ones that have some thought put into them, even if it ends up being a flop. This kind, along with the one where it's all whatever that card that lets you choose to discover a spell or minion is called just feel lazy. There is some choice involved, but it's rarely an educated choice beyond "pick the best overall of the 3" because you don't know what your opponent has/will have (until it's already on the board).