I don't know how either of us could have made our opinions any more clear...
Just curious dude. "perform like hell" could go either way.
Don't use the 3ware/LSI SATA RAID controllers in RAID 5 or RAID 6 mode if performance and reliability are of concern. I only use hardware RAID because performance and reliability are my concern. I am told that the Areca cards are much better on RAID 5/6 but I have no first hand experience with them. While you may get better performance with write-back caching (don't enable without a BBU), the improvement is incremental. Stick with RAID 10.
Somebody at IBM must not have gotten the memo then as the M5015/9260-8i is their top of the line on-board RAID controller. :-)