@steveng I definitely prefer KBUSA bells to KBK bells due to the geometry of the handle and window. The window is larger allowing for a deeper hand insertion, placing the bell lower on the arm/wrist that feels great.
That being said, the value of the KBK/BOS adjustables really can't be beat...
@kla2 Around 36kg is where a comp bell is completely solid steel and above that weight they are filled with some lead to get up to 48kg. So around ~36kg