There are two different kinds - the ones that do the whole floor, except the edges (I'll call them floor sanders), and the ones that do the edges (I'll call them edging sanders). I did four big rooms and a passage with these. Later, builders did an extension and I had the passage floor replaced and a professional to do the extension and the passage floor.
The job I did looked pretty good until the professional job was done. It still looked quite OK, but it wasn't nearly as shiny. There were 5 years between the jobs, so you would expect the new job to look better. And they probably had an easier job sanding the floor. The boards were all good (carefully selected old boards from one house, so they were uniform and old), whereas I had been sanding a floor that had been down for 80 years, and had 80 years of abuse.
But, I guess you are asking about the sanding rather than the shinyness of the floor after the finish went on.
Our house had all the floors painted black (Japan black) because they were original. There was one spot where someone had gouged holes into the floor that were about half an inch deep - looked like they had been locked in the room and had tried to dig their way out with a chisel! One end of each hole went straight down, while the rest was splinters ripped out.
So, to begin, I used the first pass to rip off the paint and level the floor with the coarsest sandpaper. At this stage I found some floorboards had borer in them, that needed to be replaced. The replacement boards I could get weren't always exactly the right height for the floor (I needed to get 80 year old replacements, so I didn't have all that many to choose from), so they needed to be sanded down to size. Then, successive passes with a smaller grade of sandpaper each time until the floor was nice and smooth.
I used the edger in between the floor sander, so that the edges were uniform (you can get a bump between the edge and the rest of the floor if you don't take care. You also need to be careful that you sand evenly, so you don't put dips into the floor.
Why didn't I do it myself when I had the extension done? I was very busy at work at the time, and it is really difficult not to use a floor when it is the passage. It was nice to go away for a few days and come back with it done. It was nice to have avoided the fumes from the finish. When I did the passage the first time, I painted myself into the bedroom and didn't come out in the morning until it was "set".
Why was the passage done twice? The boards in the passage were cut up when the house was restumped, and it didn't look as nice as the rest of the house. So, when I had the opportunity, I got the boards replaced. It was only a few hundred dollars because the same boards were being used in the extension.
