I can say that there was no real noticeable difference since the upgrade so far except for the battery live. I have yet to charge my Nexus 7 since the morning although I had been with it almost constantly with push options turned on via my mobile network. I still have 37% on the battery indicator.
Is that a good sign? I sure hope so, even though I don't have any games installed on the unit. I had watched a few YouTube video though.
There were mentioned that battery optimisation was one of the key features of the new update. Hopefully it lives up to the billing. In the meantime, I would continue to be online until I go to bed, and would not charge until I wake up in the morning. If there is still juice, then I would be really impressed. Watch this space ...
This also made me wonder if the update on my Nexus 4 would prolong its battery live. The battery really sucks on that phone, and it would be nice if there is improvement even though I would only have wifi on it.
