The grammatical mistakes were prominent. It was pretty repetitive too throughout the story with certain things being brought up over and over again. I'm not sure if the author intended it for emphasis or not but it was kind of annoying when all I wanted was for the story to move on.
I just read through the first couple of reviews on goodreads and I'm not even sure why the book is being compared to FSoG (which I did not read). There's no BDSM in it and the sex scenes are pretty tame compared to some other books I've read. Brian Silver tries to be controlling but he really isn't in the book (if anything he tries to assert some control which Greyson just brushes off or gives into depending on the situation). He has a strong intense attraction to Greyson Black that can be seen as borderline obsessive.
The background on each character was pretty interesting. The relationship build was pretty good, although some of the dialogue was pretty corny, some was cute though in a dorky way.
The mystery of Silver and his intentions and his little secret kept me intrigued. The characters pretty much grew on me and the thing with Milo and Marcus kind of was unexpected since I didn't think Milo was involved at all. I'm not sure why there will be a sequel but I don't mind seeing more of Silver and Black.