"Acting upon release instead of press will drive the users mad, I know of sales lost for that reason. "

Not neccesarily. The user will go mostly mad IF the intended action takes place ONLY after he releases. I agree here.

The user parameter is displayed on the display and the user wants to change it.

He presses the delete key and IMMEDIATLEY the display IS cleared and waits for the user to release the key.

He then presses "A" and the display IMMEDIATLEY reflects it AND waits for the release of the key.

This method eliminates missed characters with some enthusiastic users who pound away on keypads. ( Please note I am referring to a keypad used for user parameter entry and not the one like I am typing this post - that is a different story)

you must have said what you said with a reason which most probably I missed. Or are we saying the same ?

Cheers.

Raghu