Craftsman mowers vary greatly, but share one thing in common. They are rebadged versions of a lead manufacturer, HOWEVER they are always spec'd for sears exclusively. Hence the name change.
Here is a link for all the info your looking for...
The same is true with their push mowers. Husqvarna, MTD, or Briggs & Stratton is who makes Craftsman for sears. VERY different machines and the only thing they have in common is the name.
My opinion is this...
MTD - low end
Briggs & stratton - mid grade
Husqvarna - high end homeowner
Anyway you slice it, none of which are commercial.