Basicly dcs is just another way to do what pl or subtones do.  As I
recall, Motorola came up with this so their stuff wouldn't be compatable
with other radios.  If you started out with there radios, you had to stick
with them.  They also use to letter code their tone reeds to make it more
difficult to swith brands.  I've used both and don't see any difference.
73s
Butch Bussen
wa0vjr