I have one that worked well for me for a couple of months. I had repasted the heatsink and had a 120mm fan in the side panel slowly blow air towards it.
My system started to give me some trouble though (seems like a faulty HDMI cable was at least part of the problem), and while trying to figure out what was wrong I ran the system for a couple of minutes without heatsink. I got the buzzer, but not knowing what was happening I failed to turn it off immediately. This happened twice. Now the system boots fine, unless I have the card installed. Then I'm getting "Controller failed to load utility. Press any key to Exit." With drives connected I get a couple of error messages (BlockIO-Command Failed and LBA out of range), but I can't get into the BIOS for example where I could tell it to work in HBA mode. The system stops booting at this point. (Also without drives connected, just without the error messages). I can't enter the BIOS.
Next up I'll try the card in another system, but I suppose it's gone. I can only say, keep it cool. And that means plenty of airflow. It gets really hot.
(Any alternatives that support 16 drives or more and won't bankrupt me?)