I'm having the same issue with the 1511 update as various others, the RST driver, version 14.6.0.1029, was active during the update, and now the SSD cache is no longer functional.
Unfortunately, I can't downgrade. 14.5.0.1081 shipped by Windows Update isn't functional at all (since there is no compatible UI), and 14.0.0.1143 was active when I upgraded from 8.1 to 10, which already caused the same type of issue, so that version is burnt for me as well. (I tried already. Once broken, the same driver version remains burnt until a full Windows reinstall.)
It looks as if there is something horribly broken in the Windows update process for major releases, all of the broken versions have in common that the Windows logs show that these drivers have been "migrated" - whatever that is supposed to mean. However, every single "migrated" driver for storage devices appear to be somewhat broken.