As I said in one of my updates, the word that best captures this book is "meh". Though for me, if I had to describe it in *three* words, I would say "seen it before". Gay magic-users? Mercedes Lackey did it in the '90s. Secret magical wars that normal people can't see? Harry Potter and Brandon Sanderson's Alcatraz books (which are excellent, BTW. it's full of zany humor and some interesting thoughts.). Even the various monsters are, more or less, cribbed from myths and legends. 
 That's not to say that it sucks, or anything. The fact that I was able to finish it means that it doesn't completely suck. And it was a bit interesting, I will admit. But, still, when I compare this book to some of the other books that I've read, like Misty's urban fantasy...cycle, I guess we'll call it, or the Mercy Thompson books, City of Bones suffers in that comparison. 
 Of course, if the writing were stellar, I could forgive unoriginal storytelling. But it isn't. It's not at the "shitty fanfic" level of craptacularness, but it still isn't very good. A few samples: 
 - "Magnus plucked the invitation out of her hand and looked at it with fastidious distaste." As opposed to untidy distaste, of course. I can think of several other ways to write that that don't sound nearly as pretentious and dumb. 
 - "...the plunging neckline of the red tank top only emphasized her lack of what Eric would have called a 'rack'." Look, it's not as if readers are going to say, "Oh, she doesn't have a medieval torture device?", or something like that. "Rack" is common American slang. You don't need to preface it with several unnecessary words, as if she's talking about someone's personal conlang. 
 - "The last light of sunset struck gold sparks from his eyes." WTF is this shit? Are there actual sparks coming from his eyes, because of the sun? This is the worst kind of cliched nonsense writing that I would expect out of a bad fanfic writer. Who edited this book, and missed this goddamn sentence? 
 The bottom line is that there are much better urban fantasy books out there. Read them. Don't read this. It really isn't worth it.