The first 5-6 episodes were incredible. I have fond memories of the anime "Ano Hi Mita Hana no Namae o Bokutachi wa Mada Shiranai", but this show has a more mature story and a better sequencing of events, up to the half way point at least. The actress playing Jisoo did an amazing job, I really felt drawn to her & later on even as a voice actor she was phenomenal. Feels weird that she is supposed to be a supporting actress, however Lee Hana is credited as the second lead. It's not like Lee Hana did a bad job, it's just that the writers were not kind to her character. After episodes 7-8 the writing has become aimless. I mean I get it, the ratings were bad & international audiences don't matter, so they tried a bunch of haphazard ideas to improve ratings, but I don't think that ever works, but it kind of ruins it for the rest of us. (same thing happened to When The Weather is Fine) They focused on Kang Inwook's character way too much to up the conflict, but I don't think anyone cared about him at any point in time. Ultimately the ending is reasonable (not great) and they did deliver on the sad boy meets sad girl & then they heal premise. The title of the drama is "A Piece of Your Mind", to me this means that if the writers have had the chance to develop their original concept we could have gotten a lot more focus on the AI devices. I'm thinking that the old lady that tuned the piano would have had a lot more screen time as well..
We had stunning audio-visuals and good acting performances, but then again there are quite a few side characters that had meaningless storylines. Other than Jisoo & the OTP I did really not care about anyone else, which is a shame, because the cast was great. As for the main leads, they had average chemistry, but their acting performances were great.
One big plus is that even though the "final confrontation" was dragged out, things didn't devolve into full on makjang..

Overall the 8/10 rating seems reasonable for a show this memorable despite the numerous shortcomings.