Perfect Is Boring
I love a flawed character. You can do so much with them, and there is room to grow. The more human, the better. Personally, I don't think I've ever written a character without failings. In my opinion, they make for a more interesting story.
Let's take this down to basics and see what you think –
Mina is a bit of a selfish girl who runs away from home to take a boat ride with a friend. Things go dreadfully wrong, and she ends up in Dominic's path.
Dominic's father was cruel to his mother, and Dominic never did anything about it. Because of this, he has issues with women. He is afraid he will become his father, so he avoids women altogether.
Mina needs his help, but he won't let her close enough to him to get it. She clings to him because she is afraid to go home to her family and face the trouble that her running away has caused.
Now, if you look at this plot line and remove the characters' flaws, you don't have a story at all. Take away Mina's guilt, and she can return home without delay. Get rid of Dominic's family issues, and there is no tension between them. Eliminate Mina's selfish impulses and Mina will never even leave home. Keep all these things, and you have a perfect opportunity for the characters to grow as separate people and as a couple over the length of the story. Leave them in, and you have potential for passion, adventure, and romance.
There is a certain amount of perfection in the flawed character. I will go into my heroines for more examples.
Chloe, in Bound by Love, starts out a spoiled girl with little regard for the people around her. As she sees what effects her deeds have, she slowly comes to realize that her actions have consequences, and by the end of the story she is not the same.
Reena, in Crushing Desire, is very insecure. She isn't fashionable and she knows it all too well. Joshua shows her that love dictates true beauty and by the end of the story she has changed.
These flaws bring a certain level of humanity to the characters that perfect characters could never achieve. Next time you pick up a romance novel, watch for characters with flaws. See what sort of trouble they can get into and how much fun the story is because of it.