I found this drama rather simple but refreshing in a way. I specially liked the dynamic between the characters since I haven't seen many dramas were the girl is a tomboy. I honestly thought the fact of the female lead being mistaken for a boy would make the show unbearably clichéish. But thankfully the way that aspect of the story was used made the show funnier and more heart-warming. Also, all the characters are very real and go through legit struggles.
I can totally understand how this show influenced the drama world, as it has that iconic feeling, despite the simpleness.
I looooved Gong Yoo in this, although it wasn't my favorite performance of his; his character was so funny!! I saw real development. Honestly, I loved every character. Usually, female characters in older dramas are difficult to like but "My Chan" (lol again haha) was really likeable and a good character.
It has its flaws and it isn't a drama that I would rewatch (at least for now), but I can see its quality and value, specially since it was released 12 years ago!
Don't regret watching it at all.