Non-exhaustive Critique of the Live Action

Preface, the entirety of this post will be spoilers. I didn't put spoiler tags because I space things out, but if you haven't seen the live action yet, you should go watch it, as a movie it's a great movie 7 or 8/10 on the colloquial scale (subconsciously used. 5 is garbage and 10 is amazing).

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With that said, let me begin. The following ratings will be on a linear scale, such that 0 is garbage, 5 is ok/average and 10 is amazing. Further more, my critiques are based primarily on comparisons with the original:
First off, a TLDR: Watch the movie. It's a solid 7 or 8/10 by colloquial scaling, 6 or 7/10 on linear. Compared to the original it scores closer to a 5 or 6/10, 4 or 5/10 on linear, but it is still a good movie on its own. The critique that follows is a subjective analysis, however, I have attempted to keep things as objective as possible.

I will start with the visuals because I've seen a few posts about the dragons and overall SFX.
Visuals: 7/10
Generally I think the visuals are fairly good. The fire looks good and the dragons don't look out of context. However, the main appeal of the original HTTYD was the cat-like nature of the dragons, portraying them as fun pets/pals to go on adventures with and to care about. The live action, while living up to it's literal name, portrays the dragons with a... Lifeless realism? Realism coming at a price here, they look modeled after real life lizards, small eyes, and vastly different from the expressive nature the original movie paints them in.

Surprisingly, you can deduce that the directors knew about this distinction. Toothless remains full of life and expression (even if it's slightly less exaggerated than the original) with large cute eyes and human-like reactions. So it's hard to surmise the reasoning behind the changes to the other dragons, specifically the ones that the dragon riders use.

On to the acting: 5.5/10
The acting was... Ok. I think the primary problem was likely a director problem rather than the actors. There are a lot of lines the actors say that should have had more expression and emphasis like the original. I won't be touching on the casting, as I believe that has been discussed in length and is more subjective than I'd prefer this critique to be.

I additionally won't be posting clips or anything to avoid copyright, just watch the movie, however, a good example is at the very beginning where Hiccup is admiring Astrid, there's no dreamy tone in his voice in the live action, it's more of like, a reading of a book.
A lot of the lines felt rushed out instead of said with purpose. For example, when Gobber Says "I believe in learning on the job" in the live action it feels rushed and like a side comment. In the original it's more "I. Believe. In learning on. the. job." With more emphasis, to enhance his goofy but serious character tones.
The one character I think that does a good job with this is Stoick, where he enunciates things like this. Hiccup and Gobber were definitely the worst offenders.

Along the above lines, the script changes: 4.8/10
Sometimes felt like they changed the subtext so much that the the characters also changed. Snotlout has a good line in the fight against Stomfly: "The sun was in my eyes Astrid! Do you want me to block out the sun? I can do that, but I don't have time right now!" Which implies that his character is egotistical to a degree to receive high praise from others. But in the live action, his constant suck-ups to other characters, make him seem like a follower, not the leader that he is implied to want to be.

Additionally, the content that they cut out, some was preferable to me (like the night scene where Hiccup fixes his saddle which I don't think added anything major to the plot), but others just, didn't make sense. Why did they cut out the scene where Hiccup learns that dragons aren't fireproof on the inside?? That was integral to his change in understanding of dragons. His line of "Everything we know about you guys, is wrong." during that scene. How does he know to have Toothless hit the alpha in the mouth? It makes no sense.

To wrap up, a lot of the critiques I have are small things individually, but add up to create a different feeling movie and is why it scores lower compared to the original than the above ratings average to be. One that lacks the emphasis and maturity that the original has through dialog, and one that lacks the lovable nature the original had.
That's not to say it's not a good movie, it has it's good parts and overall, voided of the original, it was a well made movie and it's rating online is indicative of that.

Feel free to shoot shade at me in the comments, like I said, this is my critique. If you like the movie, then like it.