You are not wrong in reiterating the theoretical performance benefit of a RAID setup, insofar, as you remember to clarify one thing, which you didn't. And this is: Under, realtime usage, the theoretical performance advantage that can be directly attributed to the RAID setup is likely to go unnoticed by the average home PC user. Also, the associated cost with a RAID setup, when you consider the extra hardware requirement more often than not discourages its implementation.
Even for the gamer, the setup isn't all that compelling. Sure, your games may load a tad faster, but are you getting a higher FPS because of the RAID level setup? Nope. A faster video card & CPU are still the key determinants of maintaining the smoothest gameplay. And in baldybob's case, implementing RAID is probably going to negatively impact his gaming since he's got a built-in RAID controller, which implies, that the load that a discrete RAID controller would have handled will have to be handled by his CPU, much to the detriment of the CPU's performance & quite possibly his FPS. And all of this is not even considering the potential risk associated with a disk failure.
You need to rethink this whole thing baldybob.
Jabbering Idiots: Everywhere You Look!