I've had my 5900X since about February. Though I've got the weakest cooler between us 3, a NH-C14S. It's a little souped up from airflow in this case and a 2000rpm Noctua industrial, but still the weakest.
I'm guessing
@freeagent 's gonna be using his beefy FC140 or Macho RT so he'll be the one offering stiff competition for your D15
5950X behaves a bit differently though. Stock ST might run same or a little hotter from slightly more per-core power and higher freq (slightly, like 50MHz or less), but stock MT is a bit cooler, I guess lower MT per-core power helps.