Dual evaporators prevent mixing the air from the freezer and refrigerators. This prevents transferring odors and even taste. This can't be done with a single evaporator.

Dual compressors give you redundancy. It is highly unlikely both will break at the same time so you will have at least a refrigerator or freezer.

Dual compressor systems have a performance and efficiency advantage over one single speed compressor refrigerators.

A variable speed compressor has a small efficiency advantage over dual compressor refrigerators. It is debatable which if either has a performance advantage.

A year ago all Monogram refrigerators had the ClimateKeeper2 system. Dual evaporators plus one single speed compressor. It seems they no longer give the specification on compressors and evaporators.

Having said all that GE does not have a good reputation when it comes to refrigeration. They announced some major changes to their freestanding refrigerators including bringing back some manufacturing to the US. I have not heard of them making changes to their built-in line. If you are not getting a big discount, on the magnitude of 40% or more I would look elsewhere.

This is a long term investment. If something major fails within 12 years most people replace a freestanding fridge. Most people will repair the built-in unit. And keep repairing if something else fails. So you are entering into an expensive long term relationship with your built-in fridge :)