Notchy or 'cog torque' is not neccessarily just from a strong magnet or a good thing in a motor design. It is simply the attraction of the magnet to the stack teeth when the motor is not being powered. That same 'drag' is present when the motor is running which is not a good thing overall.
Slotless motors have almost no cog torque, but can have very strong magnets. So you cannot really judge a motor by how hard it is to turn the shaft with your fingers. Some people go to great lengths in the designs to reduce the cog torque.
Our slotted 1/10 and 1/8 motors have very little cog torque and very strong magnets. Smooth low end and plenty of power.
Tekin Prez