I liked the main actors, all 3 of them did a great job. The production quality had been quite excellent as well. 8 episodes to tell a proper story forgoing cliche twists could have been great. Naturally the biggest weak point is the writing. It's really strange, I must once again question the qualifications needed to become a kdrama writer. The writer is certainly not lacking in creativity. There are some outstanding ideas in the drama, the bare bones frame of the story is pretty good. It's nice that the magic is not over explained, I think this is the reason why the original Star Wars films were so good and what followed later so much worse.. The reason why the writing is ultimately weak is that the pacing is just plain bad and the first 2 episodes were pretty boring as well, focusing on things that are not fun to watch and very Korean in a bad way.. So yes, the pacing. The drama only has 8 episodes, but the first 6 were extremely slow. In episodes 3-6 the drama followed a one wish a week format, but unfortunately the individual backstories of the applicants were not all that interesting, or well acted out really. With that in mind, why just why are the last 2 episodes so rushed and so lacking in impact and emotion. I did not feel much of anything upon finishing the last episode. *shrugs*

Mystic Pop Up bar is a fairly similar drama, but it's hugely better. The writing is much superior, it's much easier to empathize with the characters. That show caters to the Kdrama genre's strengths much more.
Then again Witch's Diner is worth watching just for Song Ji Hyo. Her clothes and her significantly different looks were quite a sight.. (her acting skill too, I guess :P)