Honestly, I was pleasantly surprised with this book. Maybe it's not the best Harry Potter fanfiction ever written (I haven't read that many to make a judgement), but it's enjoyable enough and at times, hard to put down. I like James and his ultimate motive to escape from the shadow of his legendary father. I also like how Teddy Lupin and The Gremlins were written, it seems fit for me to think of Teddy as some apprentice to the Weasley twins' mischief (but no one can surpass the Weasley twins...really, no one can). James Potter's besties (Zane and Ralph) are likable too, but not as developed as Ron and Hermione were. At times I think they're overshadowing James too much. I understand that this might be deliberate in order to focus more on James' insecurity to live up to the magical world's expectation, but sometimes it's too much. It's nice that Zane and Ralph was sorted to other houses though. After the downfall of Voldemort, I think it's normal that the enmity between houses are somewhat cooled down...um, a little. 
 I can accept some alteration of canon and its reasoning. I can accept Zane being American, and the visit from Alma Aleron (the wizarding school in United States) along with their quirky professors, although their students were really a minor-almost-nonexistent part of the story. I can accept that younger students were taught harder subjects (like Arithmancy. Even the genius Hermione took it when she was, what, third year student?) I can accept James sharing room with older students, and only squirmed a bit when that professor from America tried to explain the science of magic (I know it's a nice attempt to explain about magic logically, but it's really making magic un-magical). However, some things keep bothering me from the very start. 
 First, There is just a little sense of difference in psychological development between younger and older students. I think it's a very important aspect that made me fell in love with Harry Potter series, because I can feel they grow along the series. Here? James and his friends were first years but sometimes didn't act and think like one. Seems that Mr. Lippert is more comfortable writing about older students. 
 Second, I can't accept that there were more than two houses in every class. It's believable for 'new' subjects like Technomancy, which was not normally taught in Hogwarts. But in one 'ordinary' class (like Muggle studies), sometimes we have Gryffindors, Ravenclaws, and Slytherin together. That is plot-convenient, but...um, no. Just imagine how crowded the class would be. 
 Third, not only there were more than two house in every class, James shared some class with older students too. Like the said Muggle studies, James shared the class with first year Ravenclaws and Slytherins, also Ted Lupin (who was SEVENTH YEAR STUDENT), and several third and fifth year students. What did they do in that class? Playing football. *sneer* This contributed A LOT to the first point of my dissatisfaction. 
 Fourth, the Muggle infiltration part is downright ridiculous. 
 I like the idea though. Some twist were also nicely done. The antagonist is a bit like little Umbridge and has a lot of potential to be...um, a decent villain (I hate her name, though). The plot about Merlin is great and believable. I'd like to edit some part to fit better with the canon, but who am I? Hehe. 
 Overall, it's a nice dip in the magical world which is unseparable part of my childhood. I like it enough to continue reading the series. Kudos to Mr. Lippert for making this (and approved by J.K. Rowling herself, what an accomplishment). If only he would edit it a little bit... 
 (plus, it's free! :D)