I would categorise this drama as 'slice of life'. It takes it's time to develop each scene and shows the characters life as it is, their struggles and frustrations.
We can see the male lead's frustration. A sprinter who is fighting the hierarchy system in the sports industry where seniors bullying juniors is the norm. He tries to go against the system and fight with the abilities that he has while upholding his beliefs which could end his sports career. He exhibits extreme control over his emotions, I feel it's more like he feels dead inside probably due to his upbringing with an absent superstar actress mum and an oppressive dictating politician dad.

I do appreciate that almost everyone behaves like an adult. The don't go off the rails at any misunderstanding and do speak their mind when it calls for it. There isn't an instant love at first sight, this drama takes its' time to develop friendships and relationships. Although each episode runs around 1 hour, it does feel longer than that. Despite it's slow pace, it isn't boring.
If you're ok with slow burn dramas then this is right for you. I liked Run On, but i wasn't obsessed with. I enjoyed watching it but I don't think I'll crave watching it again.

As for the acting, I think this is the first Shin Se Kyung work that I liked and I think she should pick more of these strong adult roles although script availability is another matter.