RAIDframe performance vs. stripe size

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

Does anyone have some real-world experience with RAIDframe (Level 5)
performance vs. stripe size?
My impression would be that, with a not to large number of components (4+1,
in my case), chances are rather low to spread simultaneous accesses to
different physical discs, so the best choice seems the file system's block
size.
On the other hand, the Carnegie Mellon paper suggests something around
        1/2*(througput)*(access time),
which would amount to more than a Megabyte with my discs.
So, what are the real-world benefits of a large stripe size? My application
are home and mail directories exported via NFS.