what does a nand backup and a bart backup do?
Backups - Nandroid vs BART - Android @ MoDaCo
In a nutshell, nandroid makes a copy of the internal storage of your phone. Bart adds a seperate file containing apps, etc. Nandroid + ext is essentially the same as a bart.
I've always run nandroid + ext and whenever i've restored, the restoration has been perfect, including apps installed on the sd card.
running Nonsensikal 16.1