Strange statment would I say : If a backup functionality is provided in the image, the least is that the restore functionality does its jobs as well ...... Do not see the added value of a backup without a correct restore ....
Depends on how you look at things.
There is no backup that is able to take 100% into account the
changes within the image or OS with PC .
This is the reason why in the standard OS systems
All is not functioning as it should after backup.
That's why you need example to re-install a plugin that during installation
make certain changes, add or Overwrite existing lib or something similar,
that is not working properly after backup.
So there is no 100% backup in any system when it comes to changes
within the system and addons.
Of course coder has made everything possible to have good backup,
but this does not guarantee for 100% backup.
another example:
Let's say if I make changes in the skin coding
which do not comply with certain plugin but with new changes within the image
This plugin will not work correctly after backup.
Or if you have some changes in image coding
not in relation to the backup plugin.
Coder certainly does not test all plugins but working on image.
It is the task of the plugin author to make necessary changes for new images
and new changes...
e.t.c
Clean image is still a better solution
and slowly add plugins to know where the problem arises..
They are always beside plus for backups also negative for backups.
So a matter of choice. Nonetheless choice, with it should be taken into account.