The SILI driver passed its basic port multiplier tests with no corruption. I did a copy chain on a 3.2TB stripe across 4 disks over a period of a day and a sweep of the HAMMER filesystem showed no corruption afterwords.
I am continuing to do more extensive tests. I haven't tested with significant popping and insertion of drives yet (idle drives in the same PM containing the drives under test). That is planned. I'm comfortable with both the SILI and the AHCI driver now. -Matt