It's nice to get your batteries all sorted in one place so they're not just sitting in a pile and corroding. I also like having the tester. I found that I had a bunch of dead batteries sitting in my storage area.
I do wish there were less compartments for larger (C & D size) batteries and more compartments for smaller (AA & AAA) batteries. I was only able to fit about 1/3 of my AA and AAA batteries in the unit and I have a bunch of empty space I can't use.
Also, when I filled one row with AA batteries, the AA batteries I inserted in the second row don't fit in the slot very well. I had to either push them down hard or just leave them sticking out because they don't slide all the way to the bottom of the slot. If I take a battery out of the first row, they fit fine (??).