I have 120 rigs on 5 cards on ds3p sadly 
Frightened by your post, I started update on 970a-ds3p on only one rig with 4 cards, but it went good and it was a notable increase in hashrate. Then I updated other two with 5 cards and everything went well, so I can't say it doesn't work. Maybe because I'm running SMOS on old 80-160GB HDD's ?