We present Monte Carlo simulations for the dynamic response of a submicron linearly graded AlxGa1-xN metal-semiconductor-metal (MSM) structure, and compare it with a uniform GaN MSM device. Both electron and hole transport, as well as circuit elements are comprehensively included. Our results demonstrate enhancement in speed and frequency bandwidth. The improved response, despite additional alloy and multi-mode scattering, arises from the capability of rapid hole removal from the device. The 20% reduction in the turn-off time for a 0.25 μm device could, in principle, be further enhanced through the use of more complex nonuniform grading profiles.