I use SirusXM almost every day, and I haven't really noticed any difference since the update. The performance has been pretty poor since the day I got the car, probably the most disappointing aspect of the whole vehicle, especially when I use other systems (friend's car, rental car, etc) to compare.
I got this update today and on my first drive with it I kept getting a USB unplugged message popping up near the top of the screen.....I don't have the exact message but had never seen it before today.