This wasn't in your list of choices, but for me, I'll never buy another controller card that's not an ATTO. You're going to see similar specs from many different manufacturers, but the difference with ATTO is the support. I bought an R680 card that started acting up after about three weeks. I called tech support, described my problem, and I had a new card on my doorstep at 8 AM the next morning.
Ask the company you plan to buy from if they cross ship an RMA. If they don't, expect to be out of business for at least three days, and expect to pay your own overnight shipping both directions.
I mistakenly bought a HighPoint Tech RocketRAID as my first controller card. It went bad, and it took THREE WEEKS to get a replacement. Oy!
Another option is to buy from a VAR that has great service after the sale, and maybe you can get an ATTO-like experience, if they have the same committment to customer satisfaction.
If these aren't important considerations, then please excuse me for butting in.
Jim Curtis: I have already purchased the ARC-1882ix-12-4G and think it works quite well for my purposes.
My HPT card worked quite well for a while, too. But, you've already read my sob story about that. I wish you continued success with it.
Harm, ATTO has yet another RAID level... DV RAID. Yet, nobody seems to be endorsing its use for video, even though it was specficially designed for it. RAID 5 is still the choice of four out of five doctors, with RAID 6 as a fallback for the risk-averse.