I agree 100%. If you are a casual user that just needs extra space, do not use RAID 0 (double the changes of complete corruption). If you are a gamer who plays games frequently or uses other very intensive applications that use allot of disk (photoshop on 5gig graphic images, etc) I would stay away.When using raid you need to have a reason for using it or you are simply increasing the likelihood you will get problems with out actually gaining anything from it. Raid is good for people who need fast access for music or people who play games. I have noticed games installed on my raid set of HDDs will actually load nearly twice as fast as they would on my C Drive.
But one thing I did notice, and the reason why I use a standard IDE HDD for running Windows on. Is that it does manage get data corrupted from time to time as I would have a problem with windows nearly every month or so that would make me either need to reinstall Windows or replace some files that had simply just disappeared or become damaged.
So if these are your only HDDs I would highly recommend that you leave them on there own since what good is windows booting up in only one go of the little blue bar when you need to reinstall windows ever month.
Besides a disc-to-disc transfer is much faster than a partition-to-partition transfer so leaving them on their own does have its benefits.