Jaden

Yes, if you get past ep 20~ish and still not getting into it, then it might not be for you. Certainly this drama doesn't seem to be for everyone.

To answer your question about why it is rated so high, keep in mind the difference between liking a drama and simply not being able to get into it. You look below in the comments and all you'll see is either:
1. Praise
2. Not my cup of tea
3. Too complicated
4. Wish there was more romance

Majority of people who don't finish watching due whatever reason listed above, unless they have some innate hatred towards cdrama, will choose not to rate it all and thus the high rating, rightfully so.
Pretty much anyone who was able to last through the whole drama has something meaningful to say about it.

Is this inspired by Great Expectations?

I was a fanboy.

That's gonna be hard to beat.

Comedy, seriously?

Good drama, bad politics.

Divide by 2, each episode is short.

Ah yes, the quarterly historical melodramatic romance, can't live without it.

It's not surprising people prefer a more emotionally-driven story, but fact is, this does not live up to NIF1, but it doesn't have to, it's very different and has its own charms and it's still a great drama in its own way. For a true masterpiece however, this is not it. Just because it give you the feels more doesn't necessarily make it better, but it's fine to have different criteria.

MCS is both wise and smart, PJ is only smart, TS is only wise.

PZ is a lesser version of MCS, but he also has both intelligence and wisdom, just worse.

If you count wisdom as intelligence, MCS is clear winner.

I watched this when I was young and really bought into it back then, however, watching it again, it's actually very ridiculous and filled with plotholes/illogical stuff, I still enjoyed it but you really have take it for what it is to enjoy it.

No, just no...

It really gets exciting after ep. 50 when everything starts unfolding, you'll have to have some patience but it really pays off. Personally I didn't find it much of a slump because I was already invested into the characters at that point. If you're really not feeling it at all then might be worth dropping, otherwise, you'd be missing out on one of the best/most underrated sageuks.

I also felt a slump during those episodes, I found it gets better later on.

I don't know why but I cannot watch any drama with her or Nicky Wu in it.

Love o2o, I've been dying to find a 3rd like these.

Is this more similar to Empress Ki or Six Flying Dragons? If it's the latter, that might explain why it's hard for me to get into it. I need some inspiration if I'm going to get past the early episodes.

Is the 2nd half better than the 1st half? I watched a bit of this and honestly, it just seems like a cool thriller but nothing special, the villains seem like cartoon villains with the cult and all.

I remember dropping this and I think it was because of the female lead, wish she was more evil/ambitious, usually makes this type of story more fun.

I've recently come to believe that good drama only have bittersweet, sad or open/inconclusive endings. This drama showed me otherwise.

It has some of the most complex characters, and teaches about all the right things: forgiveness, love/sacrifice (typical theme, but shown beautifully here), and perhaps the highlight of it all: doing something bad for the greater good, to govern a country requires some degree of ruthlessness, and this is true in reality.

Some of the best villains I've ever seen, very realistic motives and very realistic actions, the only villain that might have gone overboard you could still sympathize with. I grew attached to basically every character, including the villains.

Never felt so happy for the all the characters when they got their happy endings.

Most underrated k-drama imo.