After years of working with WordPress I tried a lot of different backup-tools. Especially when the websites gets more complex, like with using wpml, woocommerce / jigoshop or multisite installations, most of the free backup-plugins I know don't work properly anymore.
x-cloner is not as easy to use as and looks a lot more complex than the other backup-tools. But it works without errors even on multisite installations.
Thanks a lot for this properly working plugin!
Anyway, concerning the GUI I would recommend some kind of user-friendly design ;)