akcable

Got a 03 E500 and am wondering if I should do the latest firmware upgrade. The euro command unit is set to 211ece and plays DVD video (not in motion), has RDS, and can play MP3s in the 6 disc changer below. I've got everything I need right now. Here is my question. The car is due for service. Since I like to upgrade things, I was thinking I would switch back to 211us prior to bringing the car into the shop and have them upgrade the command. After I get the car home, I plan to revert back to 211ece. Will I still be able to watch dvds like beforel? Will the upgrade turn off the dvd video option? TIA