Some spoiler-free comments:

This is great fun, it’s very addictive, and once you get started, you kind of have to finish it.
Credit goes to the actors, specifically Darren Chen as Tang Fan, Fu Mengbo as Sui Zhou and Liu Yaoyuan as Wang Zhi. Tang Fan is just adorable and annoying enough to be believable, Sui Zhou seems cold and unfeeling until you realise how much of that is PTSD, and Wang Zhi is just so layered as a character it’s amazing if you think that Liu Yaoyuan is just starting out in the business.

Special mention goes to Huangyang Tiantian as Dong'er, great performance.

The set design, costumes and cinematography are also out of this world – money was spent on this and it shows. I didn’t think for a moment I was looking at some sets until I saw some behind the scenes footage, because I really believed in the city I saw on the screen.

Basically, it’s a lot of fun, and I’m definitely going to rewatch parts of it.

SPOILERS FOLLOW

The good: I’ve already mentioned the actors, and truly, the actors are everything.

You really believe the growing friendship between Tang Fan and Sui Zhou, and Wang Zhi is endlessly fascinating. Dong’er isn’t as annoying as such child roles frequently are, and there are scenes of hers which I found really moving.
I appreciated that the boys did not get love-interests to distract from the gay, with Duo’erla ending up being a friend, Sui Zhou’s arranged marriage coming to nothing, and Tang Fan, bless him, being oblivious even when he’s in a brothel being felt up by a prostitute. I would have liked more focus on their relationship, but I’ll get into that when I discuss the cons.
It’s a pretty engaging story, for the most part and I liked most of the storylines and the mysteries . . . kind of.

The bad:
I frequently mention the problem of pacing in dramas, especially when there’s hardly any. Things drag on for a while then they gallop to a finish. I remember complaining about a stretch of episodes in The Untamed which seemed to go on forever – this is even worse than that.
Then there’s episodes here which end while Wang Zhi has barely finished speaking – seriously, I had to go back and check because I was still reading the subtitle when we faded to credits!

The reason for things dragging is that we also have a lack of stakes in certain storylines. For example, Duo’erla gets shot with a poison arrow. Ok, I kind of care, but not much. Then some episodes later, I find out why this happened, but I still don’t care. In the middle of this whole “we have to find the antidote” storyline, Tang Fan poisons himself – why? Who knows. That gives me even less stakes, because I KNOW one of the two male leads isn’t going to die halfway through the series!
There’s so much stuff like this in the series, where I’m sure I missed something because I skipped over chunks of episodes. I mean, I almost missed this amazing set piece in the brothel, because I was so tired of the entire “We are dying REALLY SLOWLY” storyline which was obviously going nowhere – then later I realized it was for the Arras/Ding Man storyline, but as I barely cared about that, it was kind of a waste of time.

And then THAT storyline ended up driving Sui Zhou and Tang Fan apart for a pretty long stretch, and I was almost done. I had to spoil myself to make sure it ended with them reconciled. Also, one of the things that will hurt me upon rewatch is the number of times I will have to hear characters talk about the BULONG and where is the BULONG and who has the BULONGS, and enough already.

The Arras/Ding Man storyline is the one with the most plot holes, in my opinion. You would think that with an eunuch who spent three years really close to the Emperor, that someone would have checked if he was, you know. Really a eunuch. Also, he could have killed the Emperor at literally any time in the last three years – instead he arsed around until a villainous businessman and a needlessly complicated plot presented itself, which failed. Good job, dude.
I honestly don’t know if any of the above is in the novel, because I’ve only read up till chapter 7 (waiting on a good translation). So for now I’m gonna blame the screenwriters for the plot-holes, as well as Consort Wan’s army of teen girls and Qing Ge the building-jumping prostitute assassin (the massive explosion is not a plot-hole or something anyone made up – it really happened, albeit a century or so later, and historians still don’t agree on what caused it).

Conclusion

Look, I did ultimately enjoy it. On a shallow note, most of the men were extremely good-looking (I refuse to believe that the Chenghua Emperor was so hot in real life) and there were some badass and cool female characters. On a less shallow note, all scenes between Darren Chen and Fu Mengbo are gold – the animated bit where Tang Fan explains why he couldn’t have murdered anyone has to be seen to be believed – and when you add Liu Yaoyuan to the mix, it just gets better.