Someone earlier said "this is the battery Nexus should have shipped with." That made me wonder if Samsung was planning on shipping the larger battery with new Nexus' given the bad press about battery life. If they did that it would spark a firestorm of complaints from us, the 'early adopters.' So, make the existing guys happy, then the new purchasers happy.
I just installed mine and have it charging. As others reported, it arrived with about 60% charge. I think my Otterbox case resisted snapping on, it was so snug anyway. But with a bit of gentle insistence on my part, it is now reassembled.
I also purchased last week a Powergen mobile juice pack, Amazon, $34.99. If I am leaving home for a while, I have been carrying it along. I would recharge the stock battery from about 10% to over 90% in about 45 minutes.
I think my usage of my Nexus is different from most. I am an addicted reader. The main reason I chose the Nexus was the size and quality of the screen display. It runs the Kindle app well and I can get ebooks easily. Then, while I am away from home (I am retired), such as sitting in a Doctor's office waiting room, I am reading. Screen on steadily for a couple of hours or so. With my Palm Pre (sigh, I still love that Pre), I used to carry a couple of extra batteries with me.
I have not been all that displeased with my Nexus' battery life. Sometimes I would use Airplane mode while reading, with low brightness, to extend it as much as possible.
Back to the new battery, I have had it charging for about 30 minutes and it is up to over 90%, from 60%. I am looking forward to not having to plan ahead quite so much when I know I will use it on battery for a good while.
Cheers.