We present a linear robust design method (of quantitative feedback theory type) to control a permanent magnet synchronous motor to achieve demanding time domain quantitative specifications despite large parametric and load uncertainties which affect it. The linear control is compared with a non-linear design (of adaptive feedback linearization type) for the same motor. The experimental results show that: the linear control compares favourably to the non-linear one on robustness of performance and stability, and simplicity of implementation; both the linear and non-linear control have good sensor noise response. The non-linear method did prove the non-local stability of the design while the linear method did not.