One thing issue with WizTree is that drawing the result is slow for large trees (a volume with a great many files spread over a the structure) compared to other programs. For one of my local volume at work which happens to include an archive copy of a huge (for VSS) source safe repository WizTree is slower despite the MFT shenanigans because drawing the result after takes enough time to undo the advantage. Though this is on SSD - I expect WizTree would reclaim the speed crown for this dataset on a "traditional" disk, where the reduced random access IO requirements of its MFT scan will be even more significant.
Having retested not I have local access to that filesystem again, the issue seems to be when used remote via RDC, even over a local wifi network. Running properly local the delay goes away in even the pathological case.
As SpaceSniffer has no similar bad slow-down on display updates, I assume that means how WizTree draws interacts badly with the remoting protocol: either it is drawing in small steps and RDC is trying to send each update out individually so many small updates are going over the wire, or the 3D-ish look is causing issues, or both.
For everything else on Windows (network mounts, fat/exfat) I currently use Space Sniffer (http://www.uderzo.it/main_products/space_sniffer/)
One thing issue with WizTree is that drawing the result is slow for large trees (a volume with a great many files spread over a the structure) compared to other programs. For one of my local volume at work which happens to include an archive copy of a huge (for VSS) source safe repository WizTree is slower despite the MFT shenanigans because drawing the result after takes enough time to undo the advantage. Though this is on SSD - I expect WizTree would reclaim the speed crown for this dataset on a "traditional" disk, where the reduced random access IO requirements of its MFT scan will be even more significant.