I have been using my Tiptronic's to downshift to reduce speed and save on brake wear. Is their any harm in doing this ?

2003.5~AT~Sedan~Carribean Blue~Graphite Leather~Premium~Winter~Wood Trim~"This makes going to work a whole new ballgame."

 

You should only do that to maintain a steady speed on a downhill grade, not to reduce speed to save the brakes. Brakes are much, much cheaper to replace than a transmission. (The reason for using the transmission/engine on the hill, is that continued use of brakes-only in that situation could cause them to overheat and fade, leaving you with no brakes by the bottom of the hill.)

Besides, you have a 3yr/36k mile brake pad/rotor warranty.