If I can chime in for a second, you can't truly put all of the mentioned products in the same category (although there is a few cross over functions).
Extractors are very good at what they do (inject cleaning solution and extract the moisture) but it all depends on the lift draw of the machine as to how deep into the pile it will get. You will need to agitate with the extractor. Then you have to look at cold water vs. hot water etc.... (it does get a bit complicated)
I can say from personal experience that the Tornador is better than a "Bissel little green machine" at getting deep into the pile of the carpet, but the moisture you drive in there stays even after using the air to drive the solution and dirt out. BUT if you follow it up with a good ShopVac or even the Bissel (no solution) then you are in business!
The Tornador does allow you to mist the area with your solution which can be use to clean, apply dressing, deodorize etc.... but it does not have the power of the steamer to kill temperature sensitive bacteria, mold, spores etc...
Now on the other hand, the steamer does not create any type of cyclonic action to agitate or expel the "stuff" from deep in the carpet pile, from the nooks and cranny, or from vents.
To take one famous statement from Mike, the Tornador should be viewed as an additional tool in your arsenal. It cannot replace a good extractor; it cannot replace a good steamer; and it cannot replace a good interior brush....... but together, all those work flawlessly to save time and energy, which then translates into money (for the people in business).
There is nothing more effective in my tool chest to apply a quick APC solution to the door jams and gasketing, which I can then let sit for a bit, then followed by a gently brushing and come back with the solution then the air.... finished with a micro wipe down. Deep down and dirty jams which use to take me 30-40 minutes to detail now can be done in a matter of 5 minutes.
I also like to clean leather with it. It is a little more tricky with the vented leathers (AC seats) but it works like a champ. I can apply the solution and chase it out or apply the solution and use a good horse hair brush then chase it out. Same with door panels and headliners. Applying dressing to the dash and door panels is a breeze. Just need to make sure you have one that is diluted with some water. It is a better, more even application than the "rub on" process. I guess you can do the same with the tire dressing but I am currently using a gel.... not Tornador friendly.
What I use the Tornador for keeps expanding as I am experimenting with it. Again, it does not REPLACE but rather COMPLEMENTS and facilitate your work.
P.S. Before I forget, the Tornador is the champ for spot treatment and cleaning where an extractor or steamer can't really reach
