As far as wash quality, make sure that the water at the tap is VERY HOT before starting a wash cycle. Dishwasher detergents do not work in cool or warm water...it needs to be HOT. Many newer DW have a preheat function...use that if available. Also, studies show that most peope use TOO much detergent. Also, the new "envirnmental friendly" detergents are crapola!
Now, it sounds like the fill float may have a problem and you are getting too much water in the wash cycle.