Yeah, well, RAID1 is easy, but all you gain is redundancy (not that that's bad). Higher RAID levels can also improve IO performance, assuming that your RAID controller (be it hardware or software) can keep up, by striping as well. Of course, RAID 0+1 and RAID 10 aren't real difficult either, but they do waste drive space. Of course, most workstation users don't have enough disks to make RAID 5 usable. You, on the other hand, do. You currently are only able to use 50% of your drive space due to mirroring. That could be improved to over 85% with RAID5, even if you leave one drive unused as a hot spare. Yet you haven't. Why? Write performance may be an issue for you, I suppose, which is where RAID5 often loses.