Have you been trying to decide which rotary floor buffer is right for your particular job or business? The choices of floor buffers out there can be mind boggling. Even though price may be a primary consideration for which floor buffing machine you choose, don't let it be your only consideration.
First off consider what your floor cleaning needs are. Do you have both carpeting and hard floor surfaces to clean? Or just one or the other? How much floor area do you have to handle? How quickly are you expected to get a particular floor cleaning job done? Do you have to do floor polishing or burnishing jobs in addition to scrubbing? How about floor stripping-- getting that old floor finish off before restoring a floor to its original shine? If you have both carpeting and hard floor surfaces to scrub then a dual speed floor machine might be your best bet. The lower speeds can be used for both carpet bonneting and hard floor scrubbing and stripping. And the higher speeds can be used for light buffing of hard floors (but not serious buffing jobs).
If you have a lot of hard floor surface area, like commercially tiled floors in a grocery store, mall, or aircraft hangar, then 2 separate machines might be your best investment. One low speed floor machine can be used for scrubbing, and the other high speed burnisher can be used for the polishing.
The size of your machine should be another consideration. It should be obvious that you can cover more floor area with a larger diameter machine, like a 17" or 20". But, smaller diameter floor buffers of about 12" or 13" might be more appropriate for getting into smaller and tighter spots. Consider all the corners, alcoves, workbenches, shelving, etc. that you'll have to clean around.
If possible, try to rent or borrow a floor buffer of the particular size and speed that you're thinking of buying. Work with it for awhile. This is probably the best way to decide which machine is right for you. Reflect on these questions to narrow down your option for the best floor buffers for your particular job.