"Some people say that a certain consistent style restricts creativity others say it enhances, what are the arguments on both side?"

I feel a certain consistent style does restrict ones creativity to some extent. Creativity comes from the writers mind, and he or she needs to be willing to let it flow. A writer needs to learn to adapt him self into different writing styles.

Writing the same way makes one a strong writer in their particular field or in their particular style. It is definitely a gift to write they way they can. A sports writer, writes to entertain his audience, and is not the same as journalist in Economy Today. Both writers have a gift of expressing what they are best in. Each writer is creative within their own field, they know how to grab the attention of their readers and they can be creative in their particular area.
On the contrary using the same style, the writer will start to repeat and reuse the same method or approach to each piece of writing; it does not let them go wild. I feel a strong writer is one who is brave enough and confident enough and can prove that he can explore the fields and one who can adjust and adapt to the circumstances. An example of someone being constricted by their style would be my father. He writes in the English newspaper back home. His style I would say is writing humors articles. He enjoys is making fun of what he listens, sees, basically his environment and he loves to “word play” with the English language. He is too used to this certain style and if you were to ask him to write a serious piece on the issue in the Middle-East or the Terrorism or the Economic Crisis, he would really struggles to get half a page. Writing in one certain style does lead to a mental block to some extent; you’re limited and your mind starts thinking only in one way.