By "cogging" when out of the vehicle do you mean it feels "notchy" when you turn the motor by hand? Cogging is when the vehicle has a difficult time moving from a dead stop and the vehicle shudders when it starts.

The reason some motors feel "notchier" than others is due to a sintered design versus a non-sintered design.

As far as your vehicle "not coasting" with one motor over another is likely due to either pinion/spur mesh or not calibrating your ESC to your Transmitter after swapping motors.