These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
So Cool It's Awesome: The story has 2000+ reviews and is a very popular story in the How to Train Your Dragon archive on the site, with well-developed characters, intriguing plot line (complete with dozens of cliffhangers) and the inclusion of historical personages that only make the fic seem more realistic. Several reviewers have even said that if the authoress rewrote the story into an original fiction it would make an good story in and of itself. So yes, this story is very much So Cool It's Awesome!
Tear Jerker Toothless not being able to be with the female Night Fury.
The Woobie: Stoick during his conversation with Hiccup at the beginning of chapter thirty-eight "Entitled."