RVGuy, please take this response as a desire for an open discussion of different system architectures, not an attempt to tie unique trim cyclic to the cause of this accident.
The S92FBW development preceded the Bell 525 by over two years. So when developing the 525 FBW architecture, Bell studied it in depth. A unique trim cyclic is obviously the lightest and least expensive configuration. But is it optimal for pilot cues?
During informal discussions with the FAA, Bell was advised that the FAA would not certify a unique trim cyclic configuration for a helicopter. Primarily due to the lack of tactile cuing between pilot and copilot. But also due to the lack of auto pilot tactile cuing. This is why the 525 while being a FBW side stick, still mimics the function of a conventional mechanical cyclic.
The USMC also had their reservations regarding unique trim cyclics. This is why they demanded installation of active BAE cyclics sticks that could mimic the function of mechanical mechanical controls in the CH53K.
This sounds very much like the Airbus throttles debate!