I know I'll probably see negative moderation as a result of what I'm about to post (being as I'm about to talk up WHS2011 in a Linux related thread), however...
I stopped using RAID in any of my systems after I started using WHSv1. WHS2011 has the same feature -- live system backups. If a drive fails, I pop in a new one (of any type/size), boot a CD that came with WHS (essentially a WinPE environment with a recovery software baked in), select my backup (I save 7-10 days -- I forget what it's set to), and in about an hour my system is back to the state of the last backup. WHS is set to perform the system backups between 00:00 - 02:00 every night. The very first system backup is a 'full' backup, the rest are 'diffs'. I've had to use this feature on two of my systems, so far, and both were because of crappy WD drives (OOOOHhhh, I hate that brand soooo much). It came in really handy when I switched both my primary desktop and my laptop from mechanical HDD's to SSD's. I forced a backup, swapped the drives, and then restored...
This way, either my WHS storage pool (based on StableBit's DrivePool product) or my workstation HDD's can fail, and I can easily recover. It's automagic, manageable via a single UI, and because of DrivePool, I can easily increase the storage space at any time (without interrupting other users of the storage pool). /me puts on his asbestos underpants