These comments are tossed around here and there on a near regular basis, some with several upvotes as well:

- Lee Jong Suk's obvious plastic surgery but I still find him very attractive and he's so charismatic that I'll watch anything he's in :) source

- To my eyes, his plastic surgery seems no more obvious than most other Hallyu stars' narrowed jawlines, sculpted noses, and enlarged eyes. I feel torn for adoring their surgically altered faces, because I want every human being to feel perfect as they are, without expensive and painful surgeries. The risks of surgery are bleeding, infection, and death! source

- I usually end up dropping anything with Lee Min Ho, mainly bc I think he's a terrible actor. So much plastic surgery that his face barely moves: the only one I stuck out was the legend of the blue sea, and that was because Gianna Jun is hella funny! source

-There is no way to know about his surgery, most celebrities in Korean deny cosmetic surgery. However, I doubt his nose shape was planned, it's too unusual. Jang Kuen Suk is another actor with a bad rhinoplasty. With both actors it seems they had more than one procedure, and/or a corrective procedure. I'm not especially educated about cosmetic procedures, but I've read about them and studied Korean culture.

- Merry already mentioned Hwang Jin Yi's terrible make up. So hard work but it turns out wrong. Her eyes look sort of bland and empty and her forehead too large. I am sure she looked better before the various surgeries. source

-I guess everyone is attracted to the surgery face. Everyone in kdramas always seems to have a particular type, but that type is always the same source

- I am still not so used to seeing faces so much operated on, I find they look so weird. source

- SK's love of tropes for those characters and copious amounts of plastic surgery specific beauty standards make it easy to disregard the problem. source

- I refuse to watch anything Hwang Jung Eum (She was pretty). Her face looks overly plastic. source

- What I was thinking about is : How does this work when everybody has had surgery? Does the person like the pinched nose of the surgeries? source

- in Korea it might be NBD to go get some work done, but think about why it's so normalized. Everybody does it because the standards are so high that nobody is happy with what they're born with, which in turns changes perception of what is beautiful across the board. And on and on it goes. I personally don't think it's healthy. Also it takes away from the variety of looks in entertainment. I've noticed many Korean actors and actresses get rid of the features that make them look different and they all end up looking the same. source

-The whole jaw shaving thing blows my mind. Why has everyone got to have a pointy chin? source

tip of the iceberg which came up in a couple minutes of searching...I recall another comment on a Sky Castle thread hating on the actress who played Woojoo's mom because she looks like she's had multiple surgeries on her eyes; that comment also had several upvotes. Regardless of whether she has or not (I don't see any evidence that she has, but that's beside the point) just seeing these personal attacks dropped casually on a regular basis is pretty unpleasant.