I took my D4 out over the weekend and was prepared to fully discharge a battery while taking photos in the field. I had a second one in my pocket to replace it when it ran out, but on each of two days, I shot over 3,500 images and never ran it to even half of a charge.
I think there are five bars on the battery. I only ever used two. Throw in the few short video clips and the normal amount of pixel peeping, I can say I am totally happy with the new batteries.
Here's another observation: The display shows the number of shots taken and the number of shots remaining. That works fine on a 16 gig card that can shoot around 800 raw images. I had a 32 gig XQD card in the camera and looked down after a while to see I had only taken 200 photos and had maybe 300 remaining. That made me starting wondering if the camera had lost images. But the issue is the three digit character space allowed for the counters. When it showed 200, it had taken 1200.