The Z64 is very similar to the Pipo X7 discussed elsewhere :
http://forum.kodi.tv/showthread.php?tid=...light=pipo
http://forum.kodi.tv/showthread.php?tid=216110
If it is like the Pipo X7 (and Meegopad T01) then it is likely to have a 32bit only UEFI (it will be AMAZING if it has Legacy BIOS or 64 bit UEFI)
This means that it runs Windows 8.1 32 bit with no problems (and it comes pre-installed with Win 8.1 with Bing I expect)
However running Ubuntu or OpenElec requires a bit of work. (32 bit builds of OpenElec can be persuaded to boot with a separate bootloader, as can 64 bit versions of Ubuntu - though 64 bit OE builds don't have the right kernel options to work with mixed 32/64 bit environment)
The processor doesn't currently have Linux drivers for the HDMI audio system though - so I've had to use an external USB sound card. However Ubuntu 64 bit with Kodi works FAR better than it does with Windows (or my initial trials with 32 bit OpenElec)
The Z64 internals appear to have a better heatsink than the Pipo X7, though there are warnings on some sites selling the box about heat issues.
In my experience the Pipo X7 gets too hot and CPU throttles. In Windows Kodi this means skipped frames on 50fps content (720/50p or 1080/50i native), though Ubuntu and Kodi do better.
I've got a new heatsink and some heat pads coming to mitigate this. However the Pipo appears to now have manufacturing delays, and may have dubious Tablet Windows licences. I think the Minix is now likely to ship with proper licences - hence the cost.