So I secure erased the Octane -- well, actually I just updated the FW again, which is just about the same thing. Speed went back to normal. It looks as though TRIM wasn't working on my laptop even though it was supposed to be, and that was the problem. When I put it back in the e-rig speed was slowly getting better, but still not good after 4 hours.

But I performed a little experiment.

I copied some data -- 18.6GB of my static data -- from the Samsung and Vertex Turbo while they were still doing loops. The Vertex Turbo's instantaneous speeds are ~94MB/s though the whole loop. While copying the 18.6GB of static data, instant speeds dropped into the mid-50mB/s range and I could only copy to the Octane at ~78MB/s.

The 830, on the other hand, saw no drop in instant speed when reading the 18.6GB folder to the drive. And it copied to the Octane at about 170MB/s.

Pretty awesome if you ask me.