Mediocre performance.

If you have more than one unit (eg.: a RAID array plus a hot spare device) configured on it make sure you upgrade to the latest fw version. There have been perf problems in such cases.

BBU is an option you will be wanting to buy. Don't use this adapter without that.

Redhat's support site has a _very_ long discussion about the perf problems encountered with this card. My problems disappeared after the firmware update.

Vanilla 2.4 kernel needs to be patched to get this card working. 2.6 already has the driver.

If you need high performance at all costs consider something else. My boxes max out around 140-150 Mbit/sec concurrent I/O with this hardware using RAID 10 with 300 GB Seagate drives. (before the firmware upgrade they became saturated around 80Mb/s)

All things considered it's a very reliable and mature card (driver/fw/hw), if not very fast.

Works well - a couple of initial errors in the BIOS/Setup screens, but after that, things worked out well.
Definitely go with a 3ware or other true hw raid solution, than other cards that rely on OS sw drivers to work.