I would recommend these people to anyone. They showed up on time. Their prices are very low for their amount of effort, The white tumbled marble in my foyer, which had not been cleaned in over a decade, looked as good as new.
In addition, this was their second visit, their first having been aborted by their inability to find a place on my street (under construction) to park their truck. They returned uncomplainingly with portable equipment which they had to carry for a block to my house. I was not charged extra.
My advice is to tip them well. They're saving you money.