All of them lose data. XFS risks losing more data than ext3. I don't know how ext4 behaves. A more important aspect is how well the filesystem recovers from

All of them lose data. XFS risks losing more data than ext3. I don't know how ext4 behaves. A more important aspect is how well the filesystem recovers from having the plug pulled, and here they all do well. Once written to disk, data is stable in all of the mentioned filesystems. This is in contrast to non-journalling ones where an unclean shutdown can render the on-disk data inconsistent and difficult to recover.