Your stripe size really depends on what you're going to be doing. Since I do major video editing and other similar stuff with my main rig, I use the biggest stripe size my RAID controller allows. However, if I were constantly working with small files, I would want a small stripe size. Basically, if your stripe size is too high for what you're doing, you won't see any speed increase. However, if your stripe size is too low for what you're doing (like if I was doing video editing on a 4KB stripe size), then you'll overwork your drives and cause them to fail much quicker.