They have somewhat similar vibe of the adult romance, with a bit more than average explicit humour.

Slice-of-life romance of mature adults with a bit of drama and enough comedy.
- ML is somewhat lost in life in the beginning, thinking of changing or actually changing careers.
- ML are rather reserved but nice.
- FL approaches first and warms his heart. She herself doesn't need saving, she has an established life of her own.
- There's a lot of trust and mutual support in both relationships.
- Well written smart dialogs full of meaning.
- No love triangles or evil characters (there is a secondary couple in Run On).

The greatest difference is the amount of chemistry (YAMG couple is HOT, RunOn couple is very tame).

Both MLs are popular authors, both have an online connection with the FLs, both MLs find out the true identity of FLs first and keep it to themselves. MLs fall in love first, while FL likes somebody else. There's plenty of friendly bantering in both relationships. Both are sweet dramas.

Both dramas are pretty, have healthy relationships, and are full of meaningful dialogs.
Run On is more slice-of-life and comedy.

Female centered plot, sismance, women in their thirties. One of the main characters works in a IT/internet company and is very focused on her career.

both dramas' main focus is on work and business instead of romance, the leads are working together and supporting each other, modern setting, no dubbing.