Which is the better NVR?

Before taking that as gospel I would check out the specs on drives of larger sizes and seem if that is really the case.
There might be an extra platter to spin but it's not going to be much current difference
Plus if it's a poe nvr and you arent maxing it out, there is likely to be some overhead.
 
A 22TB drive has been confirmed to work on a NVR5432-4KS2

 
Whichever you pick, do NOT allow it to be directly connected to the Internet without a restrictive firewall, and do not allow direct port forwarding from the router to the NVR. Use a VPN etc... These Chinese NVRs are the source of huge botnet attacks...

Is there a guide/primer for how to set a dahua NVR up like this?