70% is still not good enough, right? If I am not wrong, then we need a 95% consensus to implement Segwit2x.
In reality, if the support manages to maintain 80% (higher is always better of course) for a period of 336 blocks straight, we'll have to wait another 336 blocks to finally have Segwit2x activated (obviously, it will only activate on Segwit2x capable nodes at first stage). Currently we are at 76.4% support - we are very close ->
https://coin.dance/blocks