I have a freezer on the bottom refer with just one door. It is a Sub-Zero
You need lots of room with the two doors that open out, and for me, having to open two doors would be a pain. I dislike the side by sides because they have no room...too narrow. I like to be able to fit a sheet tray in my refer if I need to.
My bottom freezer is divided into three compartments. Not sure if it is adjustable as I have used it for 14 years the way it is and love it. Of course, I have a full freezer in the laundry room. So the kitchen freezer on the bottom is for many things we use everyday, like breads, sandwich rolls, etc.