More heat? You are nuts. My PSU is only Bronze and I have a temperature sensor RIGHT ON it. You know how hot the PSU itself gets, while stress testing? It doesn't. It's consistently way cooler than the rest of the system. If I switched in a Platinum PSU, I MIGHT see a difference in temp on the PSU itself of 1c but I seriously doubt the temperature sensors on the CPU Cooler, GPU Casing or exhaust would change one lick.
Also, my Bronze PSUs seem to last me "forever" as well. In fact, instead of using a generic term that could mean anywhere between 5 and 20 years, let me give you ACTUAL quantification. My old PCs, Phenom II 965 Black Editions, were built with these:
https://www.newegg.com/Product/Produ...82E16817139005
In Jan of 2011. Those PSUs are still in operation(in different machines) today, over 6 years later. Still running just fine.