I have one benefits are compared to others are that you can change the height of the brushes, you can spray pre spray or encapsulate down so not needing a separate sprayer and far more economical than using a gravity fed tank and it also has a central tray that collects debris so it's easy to clean, down side is its quite heavy.
I use mine on commercials as it's very easy to use I have my 'helper' pre spray with it simple to use a monkey could drive it.
Make me an offer if you're interested.
Shaun_ashmore@lineone.net