Regarding different controllers, I've tried 2 Syba Sil 3114 controllers purchased about 4 months apart. I've tried 5.4.3 firmware with one and 5.4.13 with another. Maybe Syba makes crappy Sil 3114 cards but it's the same one that someone on blogs.sun.com used with success. I had weird problems flashing the first card I got, hence the order of another one. I'm not sure how I could get 2 different controllers 4 months apart and then use them in 2 completely different computers and both controllers be bad.
another data point..
I run two SiI 3114 based cards in my home fileserver running s10u3. I
was having ZFS data corruption issues and I suspected the SiI cards -
that was until I replaced the motherboard/CPU/memory. I didn't have the
time or patience to try to determine which component was at fault, but I
swapped the motherboard/CPU/memory and stressed it for a few hours and
the data corruption problem was gone.
before that, I was seeing data corruption issues within minutes. maybe
it was just memory, but I'll never know. I junked the old kit after I
confirmed I had eliminated the problem.