I have tried seedvault 3 times now. Only one occasion did it properly finalize. That was about 2 weeks ago. Since I wanted to upgrade now from latest Iode 6 version to version 7.4, I wanted to use a most recent backup.
This is a phone with 133 apps. The yet available older seedvault is 26 GB, on a USB stick of 58 GB.
Anyway, as I was fed-up waiting so long, I disconnected the USB backup stick. And did the sideloading of Iode 7. Now restoring the older vault. That does work indeed.
Luckily I backed up all phone data using My Phone Explorer, as none of the data were backed up by seedvault.
So far, the operation went reasonably well.