My in-laws have a Bissell and it works as well as this type of thing works.
It is easy to use and you will be grossed out at how dirty the water is when you empty it
I used to clean carpets for a living (my absolute worst job ever) and one of the first things we were taught was that water cleaning and steam cleaning will not do much for real stains. It will seem like it gets the stain out, but then a few month later the stain is back. Basically all the water/steam does is push the stain down toward the backing. Over times it comes back to the surface.
These units are great for cleaning, but not great for stain removal unless you just want a temporary solution.