I do. I have an Hydroforce Olympus modified with a 1200psi pump auto fill and dump.
Basically the same as the Alltec Elite 1200. We only really ever use it for cleaning on trashed sandstone, polished slate, porcelain and ceramics as I am not a fan of high pressure cleaning natural stone.
Most of the time it is just used for convenient rinsing. We would actually be better off with a floor wand rather than a spinner.
You can put something quite simple together using a £100 power washer and a 2/3 motor wet vac with auto pump out.