To extend the discussion that began in the New Zalman 600W Modular PSU
thread, I'd have to say the heatpipes seem more like a marketing decision than an engineering one. Not to say that they don't work as intended; just that more conventional methods would have worked just as well. In general, if the distance the heat is moved by heatpipes is no more than a couple of inches, and if the transfer of heat does not increase the exposure to airflow significantly, then there's little to be gained.
Contrast this heatpipe/HS to tall CPU heatsinks in which heatpipes provide more effective distribution of heat to a much greater number of fins, or to the CPU HS used in some of the Shuttle SFF systems where the CPU is almost the entire depth of the case away from the fins of the heatsink. (The SD11G5, for example
-- it moves the CPU heat from the front/middle of the case to the very edge of the back panel where it is easily evacuated by the fan without heating up any other part of the system.) Those are very effective uses of heatpipes.
I don't believe the Zalman heatpipe addresses the hot air pocket issue in 120mm fan PSUs that the Seasonic M12's 60mm fan is meant to do, either... though that solution is not exactly ideal from an acoustics viewpoint. (It would be much better if the 60mm fan actually turned back off again.)
In any case, the fan controller is a step back to earlier Zalman PSUs (pre-zm460) , which always seemed to have cooling as a higher priority than lowest noise. That this approach re-emerges in a 600W PSU is not the worst thing. Most users who actually need a 600W PSU probably don't need anything quieter, because the rest of their components will drown this Zalman out anyway.