I would love to keep the 970's but if they're killing performance at 4k because of this memory thing then I don't want them.
If they were choking due to lack of horse power then fair enough, no complaints from me, but I didn't drop over £600 on a pair of 970's with water blocks just to be robbed of performance at 4k because of a hardware limitation that Nvidia neglected to tell anyone about.
You realise that the 980s also suffer from a serious dip in performance @2160p.