Would love to see you testing NH-D15 and PA120 on same CPU, but that's a lot more work I don't expect you to do.
You being familiar with D15 means you know capabilities of good cooler, so what you think of how PA120 mount, fans, cooling and noise will be interesting.
Running 3600 on B459M Mortar Max and have thought of upgrading CPU. I don't game. Have considered upgrading to something like 5900 / 5900x.