There are only a few differences between the boards.
Work-surface and I/O.
The M7CL adds more motorized faders, touch screen and an optional meter bridge as well as more physical controls on the surface.
M7CL-48 has 48 analog ins, 16 analog outs with the option to add up to 24 additional analog outputs, or much more digital I/O.
The Yamaha Commercial Audio rep locally here gave me the schematic of the signal flow for the M7CL. The signal flow for the LS9 is identical.
Both boards have security features, play and record off USB Flash drives and have off line editing with software.