Thanks ldevri,
upon your feedback I have bought two of these controllers. They have installed easily and were available without a hitch.
The only odd thing is the enumeration - (I recall reading about this somewhere as being a Linux oddity):
I had expected for (Sata-) Port 1 to resolve to Disk-0, Port 2 to Disk-1 and so forth.
What I got instead was the following "mapping":
Port 3 > Disk-0
Port 2 > Disk-1
Port 4 > Disk-2
Port 1 > Disk-3
Maybe this helps someone.
I haven't installed the controller on the other box yet, and am curious to see if this is the same order