I read the webtoon/manhwa before watching the drama which made my expectations high until I saw the casting where most of the characters do not give the same "vibe" and image of their webtoon counterparts (IMO), but I liked the cast so I watched it regardless.

The acting and chemistry between everyone were superb. It was a classic rom-com, somewhat cliché in a good way. There are some differences from the original work, but it did not divert away too much from the main plot, except towards the middle and end. The original manhwa could have easily been a 16+ episode drama and/or one that was at least longer than 1 hour an episode. Due to the short length of this drama, a lot of interesting scenes and development were either altered or taken out completely. Even without having read the original work, I would feel like something was missing towards the end.

Some things that I wish the drama did better:
1) I wanted more Young Seo and Sung Hoon scenes, but the drama underdelivered, but I still enjoyed their scenes in drama nonetheless.
2) While I am glad the time it took for Taemu and Ha Ri to officially become a couple has been cut significantly in the drama instead of being dragged on like it was in the webtoon, it was still slightly rushed in my opinion and instead of the two facing problems together, the time jump was used instead (I'm referring to the final episode in this case).
3) The main characters/couples have only met for a bit more than a month before getting together and they are already proposing, which worked out in the webtoon since most of it was Taemu wanting to marry Shin Kim (her alias in the webtoon which has been altered to Shin Geum Hi) and there was repeated emphasis on that, but it only mentioned a few times by Taemu and none of it was in front of Ha Ri. The webtoon and drama is called A Business Proposal for a reason, but the proposal aspect was toned down.
4) I also wished for more scenes that focused on Ha Ri's and Young Seo's friendship and Taemu's and Sung Hoon's bond. There were a lot of parts of the webtoon that were cut out to fit the 12 episode limit, unfortunately.

Things that I am thankful that this drama did:
1) While the characters did not exactly match the "vibe" that I would expect, the foundation/beginning of the drama was set similar to the beginning of the webtoon and that made it easier for certain things to pass and everyone's acting and chemistry was off the charts, so it worked out since the couples in drama looked together.
2) Kim Min Gue (aka Sung Hoon) thank you for working out <3 <3
3) Altering Young Seo's rival to be her cousin and showing them having a bond was cute and the Konglish was funny. Young Seo's and Sung Hoon's "love story" was refreshing and different from most couples in dramas.
4) Ha Ri was depicted as a capable and competent employee, which was not so much the case in the webtoon that was primarily focused on her and Taemu when they were at the company.
5) Taemu came to terms with his feelings for Ha Ri much faster and in a more realistic/sensible way than he did in the webtoon. Thank you for not being a fool when it came to romance and the same goes for Ha Ri.

While this drama was rushed and definitely deserved more episodes, it was a sweet and short rom-com that is different from the ones airing and reminds me of the old dramas that were focused on romance and if you want something lighthearted and fun without too much thinking, you should definitely watch it.