I have been watching dramas(Korean, Japanese, taiwanese) for 7 years and clearly staying away from the historical genre. I am glad this was my first one. I loved it. The child actors were adorable and really drew me into the drama. I was going to stop watching after episode 1 but I decided to watch ep 2 and that really did it. I watched the drama twice already. Han Ga In is a great actress so my expectations for her were high. I have only seen Jung Il Woo in rom-coms and he delivered really well in this. Young Yeon Woo was also amazing!! This is a must watch even if you are a die hard rom-com fan. There was a lot of humor between the crown prince and his eunuch even when he got older.
Loved it, loved it, loved it. Best Kdrama I've seen yet. I think they're getting better at making them, especially the "historical" ones, as long as you don't mind the odd anachronism.