There are basically two ways to watch this show. Either as a fan of One and Only or a casual viewer. If you are in the first category then this is the best show ever and it will bring you joy and make you swoon again and again. If you are in the later group then you will not understand what all the fuss is about. You might enjoyed it as a romantic melodrama but you will more likely to find it slow, stilted and some scenes do not make much sense. A bit meh, to be honest.

But credit where credit is due, the show is good. It is beautifully shot and definitely a high quality production. The sets, costumes, lighting designs are all top notch. Acting was great from the ensemble cast. However, to truly appreciate the plots, sentiments and nuisances of this show, you will need to have watched One and Only or at a minimum a decent knowledge of the backstory.

The reason is that the story is full of direct but more often, obscure references to the prequel. There are literally dozens of them. From names, locations, scenes, music, paintings, poems, food, everything. Yes, you can still enjoy the show without any of that knowledge but it will be like visiting a house full of people who are constantly telling in-jokes and laughing among themselves. You can still enjoy the drama as is but your enjoyment will increase ten folds if you are in on the jokes.

This reference spotting also extends to character spotting. Almost every named characters in the prequel have their counterpart in the present. Some have similar roles while others have their alignment flipped. The show even go as far as stating that the ML seemed to be surrounded by people who owed him a debt from their past lives (an old Chinese saying and quite true in this case).

This brings up an interesting point, the reason why the original book was split into two separate dramas is because it is a no-no to use reincarnation as a plot device in c-drama and this is how the Show got around this "problem". Dreams and references to One and Only is now fine because the FL worked on its dubbing (clever and done well) and the modern ML's is a descendant of the historical ML's clan. So everything is squared away and fated.

Honestly, fate is almost too weak a term to describe their romantic journey. We are talking divine intervention level stuff. From their meet-cute to their growing love for each other, it is all preordained. There is no doubt that our leads are in love. They only have eyes for each other and cannot live without each other once their paths are crossed. This made the rest of the plot seemed superficial. Ditto the 2OTP, they are a nice CP but barely made a splash compared to our leads.

In that sense, the FL is the star of the show. She actually provided the glue between all the subplots in both shows. Even in her modern incarnation, she still subconsciously kept a lot of her qualities from her past life. Her likes and dislikes are all reflecting her past life. Her poise is always graceful, a little ethereal and nothing faze her. She is decisive and forthright when it comes to their relationship. She is sweet and playful with the ML and the ML only. She basically lived two lives without realising it. Ditto for the ML but more subtly.

I suppose it is unavoidable that there would be at least one antagonist and I'm afraid he was not up to the task. He was really a sad and tortured soul who made mistakes and did stupid things which ended up hurting his loved ones more than the OTP. You can't really hate him but a weak, pitiful villain is only marginally better than not having one at all.

If a lot of dramas use the last episode as a reward for their loyal viewers and load it up with fan service, this Show went the whole nine yards and it is filled to the brim with fan service (and Easter eggs) from start to finish. It gave the fans everything the prequel could not. PDA, skinship, loved-up banters and everything swoon worthy. The last episode is particularly egregious but a fan wouldn't care less and is thankful. 

OST was good but I think it was a bit overused as there were so many sweet moments that the love ballads were on constant rotation.

I would rewatch some of the sweet CP moments but skip the family dramas.