All good points, personally what I would do is if you don't have a huge amount of important data to back up is do this.
Stripe 2 or 3 High performance disks together, and then have another 2Tb backup drive. Now you could mirror to the 2TB, but most the time half your data you don't care about, so do what I do and every night backup all your documents and settings folder, desktop, my docs and any other important data etc. That way if you lose a disk you just format and copy your data back. If you can afford it do a mirror as well but often it is unnecessary. I don't run a stripe, but I do the same thing in principle with my drives.
I have about 5 disks, I backup everything important from one disk to another disk each night, assuming I only get one disk failing at any time, I don't lose any data. I also backup to dropbox, and then via dropbox to my work PC.