I love the space savings with this "inverted" setup, but in order to place the CIMs outboard of the gearbox, you risk a higher moment of inertia. This will have the effect of making the robot
harder to turn.
Some quick calculations tells me that moving the CIMS outboard will increase the total moment of inertia by about 5% (for a "long" chassis) to 8% (for a "wide" chassis) for an otherwise equally-distributed robot. For a constant turning torque, this results in a similar percentage less angular acceleration.
Takeaway: for a snappy turning response, mount your heaviest items as close to the center of rotation as possible.