Yah lol. Here are some pics I believe another user took of the OEM radiator cooler.
Radiator cooler exposed pictures from cars photos on webshots Use the navigation on the top right to see other pictures, even a cut away.
The cooler is only a small hollow cylinder which allows hot water to flow through the middle while the transmission fluid it forced along the outer sides of the unit. Its always a very common place where debris collects and causes a nice clog which leads to overall transmission failure.
Anything other then the stock cooler external cooler is better lol. I prefer stacked plate coolers vs tube fin. I only see tub fine being really effective if they have a electric fan.
Last year with the stock cooler on 80+ degree days my transmission would get to 160-180 in about 10mins of driving. But I live back in hilly area. So its alot of climbing, stop and going. I put a trucool 40k in and we have had plenty of 80+ days this year and Im pushing the truck. Usually stay around 120-140. But once I get on a nice flat open road you can see the temps drop on the gauge.