Buying a steam cleaner was one of the biggest disappointments I have encountered in this job.
I spent nearly 2K on a all singing all dancing steam cleaner and wet vac and it was useless. Hard work, very hot in confined spaces and you can't see what you're doing, and then to cap it all very poor results.
I bought mine to service the loo's in a large company and couldn't wait to get in there and blast everything shiney clean and white. They were large office and factory toilets which were completely tiled on the floor and walls with white sinks, toilets and urinals. I really thought I was going to show the janitor how to use it and all the scale and muck would be gone in an instant and everything would be left looking like new.
It hardly touched any of the marks on any of the surfaces we used it on and quickly became another piece of equipment in the garage!!
Another reason I don't like these machines is you can't see what you're doing, if you point your gun down a loo, sink, urinal, oven etc you just can't see through the steam so you have no idea what you are doing.
They are also cumbersome to get around and plug in, the attachments don't last long and 'swivel' around when they heat up and people very quickly lose interest in using it when they see the results for all the effort they have put in.
If you haven't bought one yet, my advice would be to think long and hard before buying one and even see if you can borrow one for a few days to give you an idea of what to expect.