Does the 15 pin video cable still have value and is it as good as the other video cables, so does it make any difference if I use a 15 pin cable of something else?
It will still work providing your computer has a VGA port and your monitor has a VGA input. VGA is analogue the norm these days is DVI which sends a digital signal to your monitor but HDMI is fast taking over which can transmit HD quality. Your equipments must be able to connect the various connectors to able to make use of the improvements in speed and quality.