I use this to cook mostly my meal consisting of a vegetable & fish mixture.  It works well.  I use 1/2 cup of distilled water (which in my opinion is the bare minimum).  You must always start by adding at least a 1/2 cup of water before adding any vegetables.  My veggies & fish cook in about 2-1/2 to 3 minutes, after which i run cold water over the cooker to cool it down.  The only problem i have had is getting the lid to go on sometimes.  I think it gives me problems if the black rubber gasket inside the lid is not positioned correctly, then it is impossible to get the lid on, probably because the cooker is new to me and needs to be "broken in" a little, especially the lid gasket.  If you have a problem with  the lid not shutting closed, then try rotating the black gasket a little or maybe remove it and turn it over on it's other side.  But these pressure cookers are really good, you can cook some really healthy food quickly in them.