Plot-wise these two have pretty much nothing in common. If you enjoy the acting of the female lead on the other you will enjoy the acting in the other one too. I personally found the female leads pretty similar with their over-acting characters and tacky clothing. They're similar to the point I would think they're siblings.
The core theme of both stories is the same: The female protagonist possesses a vibrant personality and relies on her intelligence to survive. In different scenarios, she assumes the role of a close relative of the strict male lead. Initially, they have a competitive relationship, but gradually they develop feelings for one another. Furthermore, a second male character, an apparently perfect individual, appears as a supporting lead in both storylines.
Both have the same writers (Hong Sisters) and even though the stories seem to be quite different you will realize that they have some points in common. For example: Like Joong Won, Seol Gong Chan is a CEO (but a hotel instead of a shopping mall)& acts cold towards the female lead but is willing to help her later on,in both the female lead keeps annoying the male lead in the beginning. Female lead feels lonely in both. I can't think of other similarities right now (And I don't want to spoil it for you).You will see while watching :)