If someone needs or wants to, the instructions are detailed enough that it would not be hard to modify to produce speed. Just replace the cheap SATA controllers with RAID controllers. Then add more controllers, the more you separate the drives into separate ports, the more total BW and the faster the array will run. If you add enough controllers then you will start running into motherboard bus limitations and you will need to replace the MB with a server MB with multiple independent high speed buses. The basic design will remain the same, but you start adding much higher end HW. You could even do this with SAS (With different port aggregators), if you needed to, but the capacity would go down and costs again would sky rocket.
Do note adding a bunch of high-end raid controllers will drastically add to the cost.
None of this invalidates the original design. Rather, It just shows there is flexibility. The original design has a simplicity and a beauty all in itself. Don't knock it for what it isn't, rather enjoy it (and use it) for what it is.
