Although I'm posting what I do..........I've been around for a while and am not looking at building a business, just the opposite. At 66 I've used most machines and experimented with the little Oreck years ago finding it amazing for aggitation but guilty of pulling out " too much " cut pile / lint which meant a lot of extra time was taken up in vacuuming and it made no NOTICABLE diference to the finished product so I stopped doing it. Having read a great deal about O/P machines I played around with the Oreck and another little machine from the US and found that great results were possible, but the lightweight machines were not up to the job.
The Oreck will overheat if you try to clean anything more than a small bedroom or similar, whereas the bigger machines will run all day as they have far more powerfull motors.
The ideal for domestic work would be the 17" or 15" O/P machines with oversize pads. There might be one available soon in the UK as prototypes are currently being used by two members of this forum.
Training for O/P'ing is minimal a kid could use them ..It's more about the chemicals to use and which pads for which occasion.
Incidentally...........if you get a low speed rotary and some pads / chemical place yourself in the middle of the room you intend experimenting on.... lower the handle to about groin area, hold it close to your body and activate the lever, be prepared to raise / lower slightly to change direction, dont try to force the machine to the side or back and forth, you just tilt it slightly and it will respond. By keeping the handle low and close to your body it's unlikely to jump away from you but remember the motors are powerful and handled carelessly rotaries could cause a lot of damage. After a while you will be able to use it with one hand when the occasion arises.