Typically (although not always) the most problematic area of performance will be the start up of the motor. Getting this reliable, smooth and consistent often requires a specifically tuned startup programme. There are a huge number of factors which can impact on the required optimisation including the inertia of the application, the specification of the motor, the power available and more.
Specification points with the motors such as inductance, number of poles and max speed all have an impact. However, equally important are application specific factors such as the operating temperature, startup inertia and energy usage limits.
The critical aspect is that optimising the controller allows it to adequately meet all of the specification points required for your application.