So it was time for a reinstallation, time to cleanup and maybe rethink a few things. I installed Windows 10 1607 Enterprise x64.
I had my old storage space running, but wanted to add an additional disk.
I had to move some disks around, hence the disks was required to have the same block-size. When running the storage space wizard, I marked the disks to add and create the new pool from 
I wanted to go for ReFS this time (some comparison here: http://thesolving.com/storage/refs-vs-ntfs-comparison/)
When trying to format the storage spage, it would switch to deleting storage space and show the following error: The parameter is incorrect: (0x00000057)
I recall having seen a similar error in Windows 8, the solution was then to create a registry key, to allow for formatning over non mirrored volumes, specifically for ReFS.
Funny think, it was still needed.
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MiniNT]
“AllowRefsFormatOverNonmirrorVolume”=dword:00000001
Download RegFile
Add the key, reboot and retry.
I had the same problem when i tested it in VmWare.
Going from 2 disks to 3 disks.
I resolved it by cleaning the 2 disks with diskpart before creating the new storagespace.