In my opinion the Zalman ZM1000-HP Plus is overpriced for what it offers. It may emit low fan noise even at full load and with very high ambient but its performance is far from perfect. Especially the loose voltage regulation at 3.3V and failure of the same rail in Advanced Transient Response testing worries me. In addition the lack of a second EPS connector in a 1000W PSU is silly. Power distribution for the +12V rails seems to have been implemented without a specific plan in mind. I also expected all PCIe connectors to have eight pins. On a model like the ZM850-HP a mix of 6 and 8 pin connectors could be acceptable due to the lower wattage, but not for a 1000 W model like this.

It is very hard for me to recommend the ZM1000-HP Plus even to someone who wants a high capacity and silent PSU. If you need a dead silent PSU and 850W are enough for you then ZM850-HP Plus is way more attractive since besides the capacity it has the same features, performs better and costs 50$ less.