This video shows a carpet steam cleaning using a portable carpet cleaner. I use a portable carpet cleaning system when I clean apartments and condos in Tampa FL. It's not my favorite way to clean carpets but the results are just as good as my truck mount carpet cleaning system. When I tell people that the dry times are just about the same between my portable and my truck mount they are shocked. The big difference is the length of hose and the ease of setup. A truck mount is a more efficient cleaning system and can generally produce more heat, but portable carpet steam cleaners have a good amount of heat to them.
In the video the portable system is setup for high heat and higher pressure cleaning. My guess is that he is cleaning at about 400psi, with the solution temperature above 250 degrees. It will get the carpet clean but it can over wet the carpet. Most portables can get good pressure and heat but they can struggle with vacuum power. It doesn't mean it wont clean good but it might take 6 plus hours to dry.
I prefer a low pressure portable with moderate heat. It does a great job of cleaning without soaking the carpet. In most cases I just use my truck mount with a longer hose setup. You can see a video of my truck mount carpet cleaning setup for a 3rd story condo.