DS12 chose a new twin bed. He wanted more floor space for his guitars, keyboard, etc. His room is pretty big, but he wanted floor space.
DD7 is still in a twin, but when we replace the mattress we'll buy at least a double.
DS10 is in a double, but it is a loft so it doesn't take up floor space.
DS 7 has the twin bunk beds in his room. He is an extra large kid 98 for weight and off the charts for height. I imagine he'll need a double soon.