Overall, Good Casting was a nice mystery drama, but it had its flaws.

I wasn't a huge fan of Im Ye Eun's love interest - he was too immature and it felt superficial considering she has a daughter; any man who is interested in her would need to really prove that he's there for the long haul for both mother and daughter.
I really liked Baek Chan Mi's love interest and I was really glad they got their happily-ever-after, even if it was kinda rushed in the end. I wanted more!

The beginning of the drama was really strong - the tragedy from the beginning was devastating and goosebump-inducing. But I just didn't feel like the conclusion packed a strong enough punch in the end from all the buildup. And what was the point in killing off a character in the last episode?! *inner rage* XD Also, the identity of Michael wasn't a spectacular reveal and anticlimactic, which was really disappointing.

The fighting sequences were fantastically choregraphed! So cool and awesome to watch! Especially the female fighters!

I've never seen Choi Kang Hee in anything, but I really liked her voice AND her acting.
Yoo In Young has usually played the antagonist in previous dramas, so it was really nice seeing her as the good character. I'd really like to see her in another drama, again as the protagonist, but a little less meek.
I really loved Lee Sang Yeob - he's played a mix of bad and good characters in the past, but this drama just kinda sealed the deal for me. He's someone I will definitely give a drama a chance for! The way he portrays emotions and his chemistry with other actors is great!

OST was nice - I enjoyed some of the songs, didn't care for other songs. The music was well placed though, and didn't bother me overall.

I likely won't rewatch this entire drama, but I'd probably happily watch F/MVs of this drama, especially to get some of Chan Mi and Seok Ho.