Just did mine. First thing I noticed is they heard my bitch about the size and weight of type. Bigger type but less bold, I'm using that now instead of bold, and the bold is actually bold, better for the sight challenged.
The whole interface is different. I like it. They are going towards symbols only tough. When on a call the red End button is now a red circle with a 40 YO phone handset in the middle.
My observations after 15 minutes in.