One major limitation that Microsoft still has in this product is its inability to extend and shrink stripes.  Any applications that require sustained levels of high disk I/O will require striping.  The main difference between a spanned volume and the stripe is how its data gets written to the disk's.  With a spanned volume the in a and I is that it is not in a a is written to the first disk until its full and then begins writing to the second disc.  This is useful in that if you lose one of your disks you have not lost all of your data, or so the theory goes.

With the stripe files are written to all of the disks meaning that you can take your I/O characteristics for each individual spindle, add them together, and, assuming you don't saturate your controller, that should be the sustained IOPS level.  Using the example from the video of four discs they should have four times better performance characteristics within the four discs configured as a spanned volume.

If you have a system requiring higher levels of disk IO and you want the ability to add and shrink stripes I would recommend going with the VERITAS storage foundation product.  It provides the ease of management that you're looking for but still in a way that optimizes performance.  (Just don't spend too much time looking at its price tag.  It might you make cry.)