I wondering ...
Why you don't mention missing RAID 5 (6) as "BAD".
My opinion, it is very bad.
The second thing that was more then surprising is 2 HDD configuration.
Dedicated Hardware RAID controllers may perform on the same level (or even worse) as software assisted with 1 disk attached.
With 4 disks you can get 300+ MBps read write.
Once, during my work in HP IT department i had an opportunity to play with few RAID setups and found that dedicated hardware controllers begin significantly outperform software assisted controllers like onboard controllers on almost any M/B when used in RAID 5 or 10 setups in system under load.
It worse nothing to compare them like you did.
Try to ran on top of your OS DB + Web serving 500+ connections per minute at least + ran some serious CPU intensive task (like C or C++ compilation) and then you'll see what you paid for with Hardware RAID controller.
But the bottom line, It is good to see that this site reviews not only i7 or HD4870 like others do.
Keep doing it