I took one to Hawaii for a week - Shot with it the whole week, and still shows no appreciable loss of charge.
When we received the first prototype units, we had one of our lucky technical team members hold down the shutter release on a Mamiya 645 camera with a Phase One digital back attached for 2,000 shots. No movement on the battery indicator. The next day we decided to put a film back on the camera (we didn't really want to unnecessarily run up thousands of shot counts on one of our demo/rental units). We ran 5,000 more shots. Nothing. Then we left the camera on with a digital back attached to it for 3 days. On the morning of the 3rd day, the battery was dead.
Clients who have experienced various camera quirkiness have seen the behavior disappear after switching away form the AA batteries to the Lithium.
One thing - as far as we can tell, the battery indicator doesn't recognize the Ejji batteries, so you won't know from the indicator how much life you have left on the battery, if you keep on shooting, at some point it will simply stop.
From our experience and anecdotal evidence, 7,500 - 10,000 shots seems realistic. It's pricy, but I cannot imagine why anyone owning an AF/DF camera should not be using this product.
They're in stock:
Phase One/Mamiya AF/DF Camera Accessories
Steve Hendrix