I agree that rotation should be enough for VR purposes, and linear translation of the subject is not strictly necessary.

Any acceleration up to g = 9.81 m / s^2 can be easily simulated, and it can be maintained indefinitely. All you need to do is to rotate the subject so that the perceived acceleration is aligned with g, or keep it at an angle, to get a fraction of g. Interestingly, for VR you don't need to simulate velocity, as it cannot be perceived by the body.

Flight simulators have been using this approach for decades now, and it works really well: http://arabiansupplychain.com//pictures/300x200/CAE-simulato...

But this system looks to have the advantage of being able to simulate accelerations above g.

PS: Is gimbal a verb now?