I don't trust kies to upgrade the firmware, and don't bother
backing up apps, froyo, and gingerbread utilize different file
systems, so if you backed it up in froyo, gingerbread won't
recognise the restore. So its a good gurantee its a clean wipe for
your phone.
I recommend only the app, app list backup, so you at least got a
list of the apps you last installed saved in your external sd
card.
As for me, I'm waiting for the 2.3.4 update to be applied to
some custom roms, then I'll update.
