Got 2 SSDs in my Asus Maximus V Formula build and both are only operating at 350 when both are reported to get speeds of 500+ read write, both are on sata 3 with ahci. Really not sure what to make of this http://tinypic.com/view.php?pic=65sr47&s=9#.VvscBY-cEuU
Edit: Nevermind, actually read the OP now What's the health like on the SSDs? And is there any firmware updates? Edit edit: Dynamic volume? You got a software RAID going on?
http://i68.tinypic.com/dvm5qp.png Not entirely sure this is a brand new OS installed so if it's done it automatically? but both are suffering and one of them is registered as basic.