Good question. I took about 350 shots - about three times what I normally do. In fact, I only normally do about 70. So, this was a lot of shooting, over a long day, using two cameras. I changed the battery twice - using all four batteries, though not completely.
I don't have a problem at all about the battery life for my normal shooting. I usually just bring one replacement with me, and don't always use it. In some ways it is like changing 35mm film after 36 shots, but more than twice that.
All the things the critics complained about with these Merrills, have proved to be non issues for me.