At first I hated the heavy metal cap that sits on top of the steam valve.  I always forgot to take it off before opening the lid, and one time it fell down hard on the floor, almost hitting my toes.  Turns out there's a purpose.  It's a visual/audio indicator of how much steam is coming out.  If it rocks too fast then I'd need to lower the fire.  On a pressure cooker, more heat doesn't cook any faster.  It only wastes gas/electricity and drains out the liquid inside faster.