Oh, where to start?
As for the writing, it should have been better edited, but it's better than some I've read. Mind you, this is style only. Content is another matter.
Characterisation is problematic: in the first part, Ana feels like a teenager with her first crush. Okay, author said that Christian is the first man she ever liked. That very fact is unrealistic, but those kind of fantasies are common in the genre, so I'll let it slide. However, she is a college student graduating in a few weeks. Her body should have grown enough for hormones to settle down. And it isn't even consistent. The unnatural thrall she slips into every time she looks at him just disappears after it served its purpose.
Christian is even more inconsistent: one minute he says one thing, the other he acts completely opposite. Most notable example being(show spoiler)
He goes on saying he won't do anything Ana doesn't really want him to, and then a few sentences later he says how they will "discuss it when it comes to that". Which means he fully intends to "persuade" her into it.
These are only examples: don't expect good characterisation or consistency in general.
Now, what most of the readers are buying this book for: BDSM. It's not my cup of tea, but I actually read a few examples of BDSM erotica in order to have basis for comparison. Ladies, I'm sorry, but Fifty Shades has a few BDSM elements at best. And no, it's not him breaking her in gently.(show spoiler)
If you want sex scenes with a little naughty spice but nothing truly over-the-board, it's OK. If you really want to give BDSM a try, take a look at this list.
But my main problems with this book lie elsewhere:
(Warning: Capslock abuse)
But the real dealbreaker was the finale.(show spoiler)
And now, another hot topic related to this book: fanfiction origins.
I studied the basics of Intellectual Property Law. I even got a certificate. But in Japan. The country where you can publish your fancomic and fanfiction. I'm not familiar with how it goes in US or UK, so I won't be getting into legal matters.
Fanfiction. I've been reading it for ten years. I've read a few examples where fanfiction does depart from the original far enough, it's practically a new piece. When characters only wear same face and name, but act completely differently. When writer only uses the world of the original, but creates their own characters. Or, even better, when they use past/future of the original world with original characters. Of course, it still needs rework, but it could be a good starting point.
Alas, Fifty Shades of Grey/Master of the Universe is no such fanfiction.
It didn't use the plot of Twilight, nor supernatural elements, but the characters remain the same. Even worse, sometimes it feels like author is describing actors, not characters:
"He has a beautiful profile. Straight nose, square jawed – I’d like to run my tongue along his jaw. He hasn’t shaved, and his stubble makes the prospect doubly tempting."
Do I need to point out whom does the "stubble" part fit? (And it's in "Master of the Universe", the fanfic this started as, too.)
A test confirmed that the text of MotU and 50 Shades is 89% the same. I imagine 11% covers the names.
I admit I might have liked this book better if the author wasn't as lazy as not to even bother to try and revise what she wrote already. It could have gone a long way.
Yes, there are some changes. But not enough.
Again, I can't really say this was right or wrong. I do believe James should have put in more effort and rewritten the story.
Another reason I can't really object is that a lot of authors that oppose fanfiction suggest to fanfiction writers to take their stories, swap the character names, and publish them as original fiction. No, I'm not kidding.
"The question is—are you getting positive feedback because you’re a really good writer…or are you getting positive feedback because some fans are so hooked on the characters that they’ll read anything involving those names (whether the writing accurately reflects those characters or not)?
One real easy way to find out. Write anything you want, using Jamie Fraser, Edward Cullen, Harry Potter _and_ Dr. Who….and then change the characters’ names before you post it. Simple. Find All: “Jamie Fraser”. Replace with: “Joe Kerastopolous”. No problemo, all your own work, and any praise you get is duly earned."
Basically, you are okay as long as you don't actually steal text word-for-word or names.
And here is what Robin Hobb suggests:
"If you're really tempted to write fan fiction, do this instead.
List all the traits of the book or character that you liked.
List all the parts that you didn't like.
List the changes you would make to improve the story.
List all changes necessary so that the changes you want don't contradict the world, culture, morality or plot of the original story.
Change the proper nouns involved.
Change the setting to one of your own.
Write your story. Write the paragraphs that describe the world. Write the ones that introduce the characters. Write the dialogue that moves your plot along. Write down every detail that you want your reader to know.
Then publish it however you like."
James might have as well followed these guidelines.
So, if acclaimed authors say it's okay as long as you change the names and setting...who am I to complain?