I've been continuously following this forum but seldom post replies. Now that Sohyun has recently made/is making two dramas, I guess it's time to make this forum active again with discussions?
For me, Love Alarm is considered a hit. Sohyun is the only known name in this project (this is the first lead roles for both Song Kang and Jung Ga Ram) so the reception is really good. It may not have a genre that's fit for a wider audience (unlike Kingdom), but it received good reviews from all ages. This is also the first time I saw Sohyun's drama in our twitter trending list. Evertbody was talking about it days after its full release. All popular korean social media accounts got flooded with Love Alarm posts. The Love Alarm app, despite being on playstore only, already had more than 1M downloads. The team behind the app is also conducting global events which manifests its popularity.
Kim JoJo may not be as popular as the legendary Go Eun Byul, but I can consider this role as Sohyun's breakthrough role after she becomes an adult. But let's also remember that it is not easy to overcome a breakthrough role with another. Some actors even struggle to get out of their past characters. I'm happy Sohyun is not only known through School 2015, but also from her other roles.
Now with The Tale of Nokdu, ever since it was announced, I didn't have hopes that this will be her show since it's already in the title: that this is Nokdu's story and nobody else. She may have been announced first, but that's because she's the most known name in the drama (JDY is still considered a rookie) but the team probably looked for Nokdu's actor first. Nevertheless, I'm just glad that the first 4 episodes showed more of her character, unlike GaEun in Ruler who looked more like a cameo than a main character. Dongjoo also showed more of Sohyun's acting versatility. We never saw her comical acting yet which I surprisingly loved to bits.
After seeing how good she acted as Dongjoo (tho she acts every character flawlessly), my urge for her to star in Miss Granny came back. I know the probability of this drama being real is close to zero, but I think if she does this kind of character, it will surely be her breakthrough role. I feel Sohyun prefers to play light and funny characters nowadays since she had quite a ton of serious and tragic characters when she was a child actress. She's only 20 years old, and admittedly 20/21 is a hard time for former child actors to transition in their adult roles. But as Sohyun said in her latest interviews, she will just leave the transition to time.
I prefer good acting from real actors than lukewarm acting from idols just for the sake of ratings anytime of the day. Also, idol actors don't fully guarantee good ratings. Sometimes it's also with the timing and more importantly the story.
PS. BTOB wasn't popular during School 2015. Sungjae even said that during his audition, to make his angry acting come out, the director (or was it the PD) provoked him by asking who is BTOB because he never heard of that group before. But due to the drama's popularity, BTOB started to become well known. So Sohyun was actually the one carrying the show from the start.
I am sorry for the long post!