I really think that it can only be seen as a benefit of having no fixed office that you really have no fixed office hours. Where by having an office many people almost automatically assume that you are going to operate by standard office hours (eg 9-5 or similar).
The great thing about having no fixed office is that the time that you work becomes the time you want to work, which really does not have to be 9-5 any more. There are many reasons why this can be beneficial to yourself but also to your business. From the business point of view, if you operate a business that maybe deals with overseas clients, because of the time difference, you do a majority of your work between 5pm, and midnight. In this case what is the point in having an office that people expect to be open, between 9 and 5 when you generally dont start your real work until midnight.
The same general idea can be a benefit from your personal point of view as well. For instance you may be an early riser, and get out of bed around 4am. As such your creative mind may operate best between 4am and 9am, which is when you find you get the best work done. How can it be beneficial for you to have an office where you need to be at 9am, and need to spend some of your best creative hours getting there.
These are really just two examples of ways that having no fixed office can be a great benefit to both yourself and your business. It really makes you think about how having an office can really restrict not only your creative side, but the most efficient way that you work as well.