I watched shortly after this came out and my recollections now are: it started very strong, with lots of fun moments between the two leads, action, and beautiful costumes. Around episode 18 I despaired that there were still 37 to go. It was much too long.
After the initial plot arc, it became apparent that it was very much an ensemble palace/historical drama with tons of secondary characters - some interesting, some hate-able, some well-realized, some cookie-cutter. It was not a romance between the two 'leads' one of whom you only see in the beginning and end. I enjoyed Xu Kai's character at the beginning, very much his usually cheeky role, but at the end found his character stiff and uninteresting. Li Yitong did ok, but her character was almost Forrest Gump-like in that she was somehow magically present anytime something of historical import was happening. As the titular Court Lady she was so competent at everything as to be unbelievable, which definitely took me out of the story and annoyed me.
Struggled through the middle, just wanting to know how the drama was going to choose to depict Guifei, and was unsurprised and slightly let down. Based on my scant knowledge of Tang history the plot was very loosely based on actual events with lots of literary license taken.

Stuck with it until the end mostly for the aesthetics - the costumes are ridiculously beautiful and historically accurate. The entire palette of the drama - costumes, sets, color grading, etc. is like an amazing collection of san cai pottery.

I really wish My Drama List had more Ratings categories - I don't watch dramas for the music??? (I don't enjoy all the cheesy drama ballads and pop OSTs. y'all can have them.) Why isn't there a category for visuals??