For me they had to be real, but I love fresh flowers so I am partial. I was in a tropical & natural setting so fake flowers would have felt off to me. They weren't really expensive and I didn't plan to save my bouquet for any reason, so I don't regret it.
If you could care less about the smell and/or have a specific vision in mind that you are not willing to bend on, then fake flowers would probably be a great choice for you. There are some high quality fake flowers out there.