I'm wondering if batch 7 will handle OC over 650 MHZ ?
Unlikely, as even the "gems" of the S7 world start to lose hash and see increased HW errors above 625.
The best way to think about this would be that the batch sevens are "factory overclocked"
They have a decent amount of time to perfect as shipping is a way's off. I'm really surprised at speed change, seems they can not be happy with a single design. This will make market on 2nd hand S7's so much harder to shop for and sell with so many variations and no + or other thing to differentiate it.
I wish they would have kept old price though. With difficulty turning nasty... it could be a hard ROI to do.