No overheating that I could tell. Water temp gauge stayed right in the middle. As for the tranny, temps were also nice and cool between 140-160 degrees. NNBS Tahoes have a trans temp readout in the DIC. My Tahoe not only has the trans cooler in the radiator, but also the GM auxiliary trans cooler in front of the radiator. I've also added the engine oil cooler, which required a new radiator to support it. That was done several months ago.
I've also been asked about the AC somewhere else, so I'll add here the same thing that I told that person. AC was not on. Vents were on a lower setting, under 50%, with recirculate. Temp dial was at the coldest setting. The air was very cold coming out of the vents. Aux was on, and my wife was using the control panel in the back seat to keep herself and my son cool.