I did not expect a good and coherent story with this premise, but this was below my already low expectations.
The drama The Beauty Inside was an attempt to replicate the success of the fantastic Another Oh Haeyong and Perfume seems like an attempt to make another Beauty Inside (which was quite entertaining still), the story is very similar, but the drop in quality is just too much. Lee Minky is not a good actor, he can only play one thing, which is essentially himself, but that character was a good fit in This is My first Life & The Beauty Inside as well. Now in Perfume Shin Sung Rok was trying to be Lee Minky essentially, even though it was not terrible, but it wasn't really enough. For reference this actor played the main villain from the classic drama My Lover From the Star, which was actually a great fit for him.. I was already kind of a fan of Go Won Hee, after seeing Welcome to Waikiki 1, but I think she shouldn't have been cast for this. Make no mistake she did pretty well, I just think that this role was miles outside of her comfort zone. A 40 something woman, who wanted to commit suicide, because of all the atrocities life has given her gets to opportunity to become young and beautiful again, sure fine, but the end result shouldn't have been a perky, go lucky Go Woon Hee, I don't think.
Now about the story, it's pretty typical in some ways. We have the dumb puppy second lead type, who just keeps pushing, pushing & pushing. Basically the writers just added the most typical classic kdrama triangle possible. Some common tropes were blatantly copied from famous dramas, for example they've taken the mysterious liquid thing from The Secret Garden (even the set and the music are super similar for those perfume related scenes), then there is the love triangle cohabitation from Jealousy Incarnate and some others.. Also I don't believe that the abusive (ex)husband character needed so much screen time in a romcom like this.

Had the show been really funny I could have ignored most of the above, however it wasn't. The physical gags involving the ajumma form's obesity were almost offensive. I'm fine with watching fat/obese ppl on screen really, but this path of trying to make fun of them isn't very nice, though I do understand that in Korea fat women are shunned quite a bit more than in the west. Overall there were very few really funny moments, which is such a shame with an actress like this, who is basically a comedy goddess, or something along those lines.

Had the romance been good I could still have enjoyed this quite a bit, but the chemistry between the leads was at best average. There are also major problems with how their relationship progressed, or rather regressed at times. There is just so much push pulling. From "I have decided that I love you, even though you are not Her" we go to "I just realized it was Her all along whom I've loved" then rinse and repeat. For those that watched the episodes as they aired this might not have been as annoying, but I watched the entire thing over the course of 2 days.

TLDR: I don't exactly regret watching the drama, but I don't feel that I've had quality entertainment, will never consider rewatching.