I have had showers and not had showers in my facilities. Having them is a convenience that my clients really like. But I recommend spraying them down with a good shower cleanser a couple of times a day and being very proactive on keeping them clean and smelling clean. I have been in many other facilities and the shower smell was a definite deal breaker if it was bad. Not to mention reducing the chance of any foot fungus or debri being a problem for you clients. Post “no glass container” signs outside the shower area. Even though we always have had and have a “no glass container” policy at all of my facilities, people still bring them occasionally without thinking about the possible consequences.
I have a small studio and was faced with the same question. We decided on one shower. It is very rarely used but people like to know that it is an option.