There is so much of it!
I am NOT DONE reading this book so please take all my comparisons regarding "this does/doesn't happen in the novel!" with a grain of salt.
Although there are some mystical and fantastical moments in this show, they cut out a number of wacky and magical events from the book (such as the three brothers' strange appearances, or the Yellow Turbans using witchcraft), as well as some other small anecdotes (such as Cao Cao's childhood antics).
However, this series has completely captured my heart. I love the aesthetics of the show, the bright colors, beautiful scenery, and impressive horsemanship. The style of acting may seem cheesy at first but it grows on you. My friend calls it "operatic"; it reminds me of a Shakespeare play. The sheer scale of this production (sets, extras, costumes, props, and yes more HORSES) is impressive in and of itself, and it's worth it to make the world of the story come to life in a very "real" and tangible way. These stylistic choices combined with the fact that I knew very little about Asian history and culture meant that this piece of work was like nothing I'd ever seen before.
I love the characters in all their wackiness and profundity. The poetic language and compelling story. It has inspired me to seek out information about the Three Kingdoms period, and Chinese history and language in general.
I'm sure there is plenty of documentation about the production of this show out there, but unfortunately I wouldn't be able to find it because I can't read Chinese (yet) :( My one scruple about this show is concerns of animal cruelty, and I wish I could find some evidence that it was all just simulated but alas, I am unable to.
Putting aside issues of accuracy to the time period (not my area of expertise):
I am enjoying this adaptation so far. It is in a very different style from the 1994 version-- the aesthetics and writing feel much more similar to a Hollywood action movie. The colors are dark and muted, and the acting is much more naturalistic. It can also be pretty comedic at times. I suppose that the writing changes they made were meant to make the show more "exciting" and/or legible to the audience, but at times the end result is that the plot is cliché and the characters become Flanderized versions of themselves (Liu Bei is humble, quiet and reserved; Cao Cao is a slimey soulless salesman).
It wasn't until I compared this show with the 1994 version that I realized how important blocking can be in film, not just in theater. Initially, I found myself thinking that some scenes in this show feel like they go on for too long, but that it only felt like that because I already knew what was going to happen. However, upon further reflection I've come to this conclusion: this story contains a lot of scenes that are essentially two people staying in one place, having a long conversation. This requires the filmmakers to find a way to keep the audience's interest. In 1994, they have the characters walk around the scenario as they talk, similar to the blocking of a stage play. In 2010, the characters tend to sit still for the whole scene, and the camera simply cuts from one talking head to another, over and over again. I find the former strategy much more engaging than the latter.
However, this show still has its merits-- it's certainly very exciting, and it tries its best to help you understand which characters out of the thousands are actually going to be important to remember. If someone were to ask me this question, I would tell them to watch 1994 first, and then once you are familiar with the "serious" version of the story, watch 2010 for the laffs.
In 1994 (and the original novel), Liu Bei joins the alliance as a respected employee of another lord (Gongsun Zan). It's not that big of a deal-- Gongsun introduces him, and Yuan Shao reluctantly offers him a seat for being of the imperial clan. In 2010, Liu Bei joins the alliance independently, which allows them to add a whole extra scene where he is stopped at the gate because he is not an invited lord. Cao Cao does a "popular kid sticks up for the new kid" schtick, and they really ham up the classism/underdog thing that 2010 Cao Cao has. This scene is also where 2010 establishes the personalities of the three Peach Garden brothers. They are just as cartoony as in 1994, but the more naturalistic acting makes them come off as even more bizarre people-- for example, instead of feeling like a scripted character, 2010 Zhang Fei feels like someone you could meet out on the street (but since no one else around him acts the way he does, you get a much clearer sense of "I would not want to be around this guy, who let him have a sword?!").
In this series of scenes, 1994 and 2010 have some of the events and dialogue shuffled around into a different order. They also change the setting where Cao and Chen have their heart-to-heart (a jail cell vs Chen's nice residence). But the most significant difference in my opinion is Cao Cao's characterization. In 1994 he is very outward about how panicked he is about being arrested. But in 2010 he is outwardly calm and does not let his feelings show. In my opinion, this unreadable Cao Cao is much scarier! Once again, he reminds me of people I've met in real life. 2010 Cao also has uncanny foresight into the events of the story, and other characters (like Chen Gong, and later Cao's family members) worship him because he seems to know everything. 1994 Cao is visibly "winging it" much more.

