I don't have the Escalade cluster or other AT temp sensor yet, so no direct measurements on my part. For "normal" driving conditions around a 175-180* converter-out fluid temp would be healthy. Conventional AT fluid resists oxidation up to about 170*. But, it's just like w/ an engine, cool is good, but too cool is bad.

Can't make out the detail of your gauge. What temp does it read there?