Im about to backup a few hundred gigs of data to bluray disks, nero is presenting me with a whole range of UDF file system versions, whats the best one to use?  I understand if using UDF 2.5, the disk is not compatible with xp, but is compatible with vista and win7, is there any advantages using UDF 2.01 over a lower version?  I also need the disks to be compatible with xp.

edit: the disks are BD-R btw now RW