Hello Doug2507
I recently got the Matrix Platinum 980 Ti and I can tell you it's a beautiful beast, I was looking online to see what the 20th anniversary gold edition offers over the matrix.
The only thing that stands out (other than it being gold of course) is it is clocked higher out of the box than the matrix. One thing I can't find is the maximum voltage NVidia allows with it, on the matrix it's 1.121v with the stock bios. I soldered the pins on the back to unlock the voltage and enabled the LN2 bios but without liquid cooling it's usesless as it runs 10c-15c warmer with stock voltage and throttles bad at 70c. On the stock bios my matrix can do 1505MHz on the core and 8200MHz on the memory.
Both have the 14 phase power delivery
Both have the LN2 bios
Both have the option to unlock the voltage and memory heater by soldering 2 pins together. (2 for the voltage - 2 for the memory heater)
Both have the safe mode button for bios recovery
Both have the 4 pin molex connector for the memory heater (for use with liquid nitrogen)
Both have the DirectCU II cooler
Both have the gpu load indicator with the matrix having the "republic of gamers" and the gold edition having the "20th Anniversary". The matrix changes color depending on GPU load and the gold edition does the same.
So all in all they are both very similar in features and options with the 20th anniversary gold being a limited edition and clocked higher out of the box.