Finally looking at this thread again, I guess you'd have to say something like, " for such and such speed, distance, and grade,,, what is better, planetary geared hubmotors or direct drive.
Which is best just depends on your needs. My needs on the street, crazy hot climate, hills up to 10% grades up to 10 miles long, speeds up to 30 mph, I'm for dd all the way.
But I'd love to see a planetary gearmotor with the diameter of a 9c hub. That would have insaneo torque for the dirt, and a bigger cover to radiate heat. I'm afraid of melting down a Mac dirt riding. I could try one in winter, but in winter I just run double the watts in my dd motor.