Okay, here are our experiences: Stay away from the cheap hardware controllers like DawiControl (both chipssets they use). Have a look at the CT (german computing magazine) artikel on that (don't remeber the issue, was fairly recent). They just don't work that well with Linux. Now we use 3ware and run it in RAID 5 configuration. Works really nice, no problems with kernels and good software comes with it. But at 350 EUR it is not cheap for a four channel IDE-RAID either.
