This is a good drama if you're looking for something light and fluffy, but with little depth. The story and romantic subplots all started off well, but ended up fizzling out well before the show ended. Some connections were made too early, others too late, and wasted screen time with filler, only to rush the climatic episode instead of giving us three episodes at the end that has that satisfaction of being able to see all their hard work pay off. Where was the smarts? The epic fighting? Where was the pleasure of seeing the villains pay? Even the ending between the two brothers felt hollow and undeserved, the resolution making me angry more than anything. His brother only felt sorry for his actions after being caught, and provided no support or redeemable qualities except for falling in love with an assassin who was bland and weepy.
As for the SL couple, I was disappointed to have such an interesting wall dividing their feelings and yet we only got 2 minute glimpses every few episodes of their relationship which didn't give me anything to look forward to or to root for.
As for the lead couple, they didn't develop so much as suddenly have an insta-love moment.
This was a highly anticipated drama as I waited for it for 2 years, and while it kept my attention to watch to the end, it disappointed, and ultimately wouldn't bring me back to rewatch any scenes.