I collect these pins, and have the Hot Rod, Space Age Cooking Pin, Thermo Pin Potato Baker, and & the aforementioned King Pin, ALL of which are heatpipes. Note that unlike the others, the King Pin has a large heatsink on the outside end to increase heat flux into the pin. The thermometer in it doesn't just report the heat around the outside end - it very much responds to the inside temperature; perhaps it's tied to expansion of the internal heatpipe.
These pins are far more effective than you might imagine, despite the issues mentioned like small surface area, low air density, etc. The proof is in that graph initially posted by the OP / @Rho - the pin decreases the time to reach temperature by almost threefold, regardless of those issues. That's real data that supercedes any supposition about those issues. Note also it addresses the comment by dcarch - the cooling is indeed also shortened, as seen in the second part of each curve, though it's less effective in this direction for the reason identified by @dtremit. This cooling is in fact used for industrially-processed meat, to reduce the time to bring it closer to refrigeration temperature by "more than 25%".
