As a man who has never read Twilight or romance novels before, I have to say that I found this book series to be very enjoyable, minus the opening to the first chapter, where the writing is so horrible it's cringe-worthy. Once the reader is able to adapt to Ana's narration, the story flows relatively smoothly. I found myself unable to put the books down, and read the whole series in record time; I finished each book in under 72 hours.
As far as the characters go, I found that I identified a great dead with Christian Grey in the aspects of his desire for control and self-loathing. Unlike the person who wrote the main page, I don't see Christian as evil - he's an antihero. I am also totally enamoured with the character of Anastasia. E.L. James does not have much skill in character naming though (Katherine Kavanaugh, ugh), but we'll let that one slide.
As far as the sexual content goes, any man will tell you that this book series is relatively tame. If you've been on the Internet before, then almost nothing in these books should be new to you. I'm actually glad the BSDM was pretty mild, because I think that's about as far as anyone would really go with that line of fetishism if they weren't into it specifically. The sexual content also blended into the story fairly well without overshadowing it - I didn't feel like there was too much or too little and found it refreshing when James pulled off some "fade to black" cuts, because Ana and Christian have a LOT of sex.
When it comes to story there is nothing exceptional, but nothing too bad either. The first book doesn't have much of a conflict besides Ana & Chrisitan's relationship, then James pulls a last-chapter-disaster that practically ruins it. This crisis is recovered quickly however and James steps into less jarring cycles of rising tension and light-hearted interludes. Essentially, there are two plots running side-by-side: Ana & Christian's tumultuous relationship and the investigation into Christian's past, which blends into the attempted murder sub-plot of books 2 & 3. The third book is MUCH better with its story, having moments of high tension and a satisfying enough conclusion.
So, in conclusion, these books are a nice read and one should check them out before passing judgement on the books or the people that read them. I, for one, really