I honestly think this show isn't as bad as most of the reviews think it is. There's been a lot of negative reviews, but there are shows just as good as this, but just more popular.

The acting was phenomenal. Yoon Doo Joon was great. I was surprised to see the stark difference between him in Radio Romance and Let's Eat. I could truly see and believe that he was sad. Most cold male leads tend to just be aloof and annoying, but he even when he was cold, the sadness seemed to radiate off of him. His character development was definitely the largest in the show, but I think that's because he also just had more room for development.

Kim So Hyun was good as usual. I didn't really notice the age difference till I starting about, but by then it became hard to not notice. Thankfully they stopped perming her hair (which emphasized her age) around that time and she looked more mature. Aside from that one minor qualm, I enjoyed her role. Her character development was there but in a more subtler form. She became a more confident writer, but other than that I don't think she really had much to develop. She was strong, persistent, and hard working. I do feel like she started to respect herself more, compared to the beginning of the show where she threw away her ego in order to the first DJ to be on time for the show or to recruit guests. Don't misunderstand, she's not a timid candy character, she just was willing to go all in to achieve her goals.

The ending felt a bit forced. Ji Su Ho's mother suddenly became viewed in a more sympathetic manner. She supposedly cared about him more than money. I think that if that's the type of ending that the writers wanted, they should have shown some glimpses of her love for him earlier.
It wasn't perfect, but it was satisfying enough.

The only time felt the show was a bit boring was during the later episodes. The beginning and middle were interesting. The shows would have been much better if writers had introduced the sub-plots (backstory/murder cards) earlier and had expanded on it.
The show is a bit cliche, but it's surprisingly not cringy either as I find most cliche shows tend to be.

The OST wasn't super memorable, but I do felt that it fit with the show.

Keep in mind that I also binge watched this, so my experience was probably different than others who watched it while airing.

All and all it's a decent show. It's definitely not the best, but not the worst either. If you're looking for a good old-fashioned romance drama this would be it.