I have everything up and running. My zpool clocks in at over a gigabyte per second reads initially but then slows down to less than 10 megabytes per second.

I've tried reducing /sys/module/zfs/parameters/zfs_vdev_max_pending per this suggestion:

But this didn't do anything either. I am using WD Velociraptors and the TLER is properly set. I realize that most people don't even know that this is available but I thought that I would get this thread started so that google can index it (the website does not have a forum and I have learned my lesson with mailing lists and spammers).