In a way, I like the pinning feature, it eliminates the quicklaunch bar, but the way it groups application windows bugs me. When I have a chat program with multiple windows, I have to go to the icon, wait for the previews to load then select the window I want. They add two extra steps to something where I used to just go down and click what I wanted in the taskbar, which makes it seem inefficent to me.
I'm glad they let you ungroup them in the properties myself