I didn't upgrade, so I can't speak first hand on performance increases. I reviewed benchmarks, and test runs, and the 3d cache equipped processors would give me a 20-30% uplift over what I'm seeing now. The thing is, I'm happy with the gaming performance of my PC. The 3d cache has a much lower impact on productivity apps, so I'd not see much of any uplift there.
My current setup is near silent, some games that push the GPU will cause the GPU fans to ramp up, but overall, how I have my system configured its silent. That's one reason why I picked the 3700X processor, it was only 65watts instead of the higher TDP of the newer processors.
Either way, its water over the bridge, as I've chosen to stand pat on my PC configuration - at least right now. I can't speak for the future. Just as an aside, this was my main reason why I opted for the M4 Max Studio over the M4 Pro Mini. Its whisper quiet, and cool running.