JBOD is a Good Raid class also - what it does is enbale you to have diff size drives:
Basically the way it works is that you have : say for example two diff size drives, one 20 gig and one 40 gig. What the JBOD wil do then is combine them as one and will see it as 60 gig.
With the other forms of Raid 1, 2, 3, 4, 5 Stripping mirroring, mirroring and stripping you need to have the same size drives.
JBOD is a good way to do it in my opinion because if one drive should crash you will only lose the data on the drive that dies, where as with Stripping since it only copies in chunks on each disk and has one prog scattered throughout several it would lose all data if one disk dies.
As far as speed It runs the same as any other drive depending on the RPM speed of the drive you get.
So in my opinion JBOD is the way to go
