Bulk and weight are certainly of interest, but this is iFixit, so let's talk repairability.

Our Mac Pro guides show you everything you need to know to replace the power supply, in 26 easy steps.

But what if you need to replace the power supply in your Z820? Remove scores of screws, some motherboard power connectors, flip some flops? ...oh wait, we're done.

We're pretty sure this is gonna be a recurring theme for this tower, so we'll try our best not to overdo the repair-compares.