Don,
I wont speak for ECA and the G950 installation at "it's time" was an amazing upgrade to TC. Here is the problem as I see it:
G950 is between $450-500k+
G600Txi are between $10-25k
G950 is airframe specific - minimal sales opportunity/minimal upgrade interest going forward (look at the Meggitt system for a real world example)
G600Txi non airframe dependent - wide market applicability, reliable upgrade/support path
G950 is married to the 2100 AP
G600Txi can drive about any AP out there via GAD interface or ethernet
I believe in the next year we see G600 based engine management approved for the TC and an amendment to the Aeromech RVSM STC for G600 equipment.
Hands down the G950 is the nicest "fit and finish" out there, for me my deciding factor was here is a plane that is already lasted 40 years. ADF, RMI, NDB, Loran, etc. They have come and go. The avionics need to be change in the plane, not the plane change around the avionics.