If you like obsessive male leads, melodrama, and multiple main characters, you may like this show.
I personally love this show and have watched it multiple times.
The ML is definitely obsessed over one of the FLs and, while not good in real life, in dramaland, if you can suspend your sense of reality, it might even be described as almost romantic, in a very obsessive way. That said, he is also brutal in his dealings with others and got to the top by sometimes doing things that are not ethical. So he's certainly no hero in the general term. But his ending is pretty good.
The FLs are good, but actually I wanted to write this review to primarily mention Eun Bi, the male leads youngest sister. She was a bully, but of all the MLs family, she was the least bad. Honestly I think she sincerely cared for every single member of her family, whereas her older sister and mother were completely self absorbed and didn't care about anyone, and her brother was completely- well whatever he was. To me, Eun Bi stole the show, and besides the main couple, I most looked forward to scenes with her in it. She was funny and helped move along the plot. And I was glad there was one person in the ML family who I didn't absolutely hate. Once again, not a hero, but I really enjoyed her character and want to give her a shout out.
The person I hated the absolute most in this show was the mother, and props to the actress for playing her so perfectly. The mother was actually the main reason I had any sympathy for the ML and his siblings at all. With a mother like that, it's no surprise how messed up the kids are. The male lead was constantly berated for not being a lap dog and doing everything his mother wanted exactly as she wanted it. The children never got an ounce of love at all. And it makes sense why he would obsess over the FL who is so opposite of the mother. In that sense, the mother character made the plot make sense and is a very valuable addition.