Having about 500 hours in a Cobra front seat, and also lots of time on Comanche and research helos with side sticks, I can say that there really is no difference. The location of the stick is not the driver, Spaced. For those aircraft, the cockpit packaging made the side-arm attractive, but where the stick is is not important, what it does (the stability characteristics of the aircraft0 are everything.
BTW, I believe the NH-90 FBW has a normal center cyclic.