Really enjoyed this fanfic!

General spoilers, nothing too specific.

Art was wonderful!!
I thought the collection of letters were hilarious, and a great way to have the characters be together while being actually apart and also a great way to demonstrate their past relationship and current connection to each other. Plus, I think it was fabulous to show how Sirius and Remus were on paper versus how they were when together in person.
Yes, this is certainly a slow build, as stated the description I read before I started, but I liked that because it really gave an impression of how their friendship was and what was going on in both of their lives--it was a scope of this time, for both of them, and we as the reader got to experience a lot of prelude before Act 1, which was wonderful for me!

This fanfic also made me see why people love the Marauders so much. I always thought they were cool and of course I'd read anything JKR would write, but I wasn't desperate for their adventures or to find out more about them, not really. But this was just a taste of all the alluded-to exploits and a sample of how they were together and of their unique personalities. Loved it, want more!
That being said, the author(s?) claimed that Peter wasn't stupidified, but I have to say that I mostly disagree. He was the least discussed character and was the butt of the joke and often said stupid things. Yes, there were moments where he was part of the gang and had not-terrible lines, but I don't recall even a single instance of him being portrayed well: he was always tagging along and contributing bad jokes and being the fat one and dumb and unconcerned and not following the thought process of what was happening around him. I know there wasn't a whole lot of cannon to base his actions and character on, but this book was like a trio with a random hanger-on who was only allowed in because he was in the cannon.

Finally, the actual physical relationship between Sirius and Remus was also fantastic, as it felt so real! That conversation about making out despite being sick, and snot and all that, SO PERFECT and true to what would be happening during this secret, new and exciting teenage relationship! I thought the author did a great job of putting in just enough to be tantalizing and titillating, but also to have it be cute and romantic and not too explicit.