RAID 5 hardware config or RAIDz?

[CharlesRutledge]

I have a PowerEdge 2950 with PERC6i controller, six 2TB hot swap drives configured RAID 5 with one hot spare. Is it best to configure the RAID on controller or install FreeNAS and use RAIDz to configure? With the setup I currently have, I have 1 volume that is 7.2 TB.

Thanks