I am not using RAID anymore, takes long to boot with AMD chipset. I'd setup RAID with INTEL anytime.
I'm sure you haven't had That bad boot times using an AMD raid controller... Lowfat or anyone else (me like) that's used an separate controller knows how long it takes a system to boot when its "Bringing up the controller...". It can hang for 10 - 15 seconds if not more, lol. Now that's a bad bootup time, hehe.