I like to keep the sidebar closed when I can (I usually have Asana in a half-screen window, not full-screen, so I need the real-estate for the task list and details).
Moving the links to My Tasks etc. into the sidebar means that instead of one click to get to those views, it’s three: open sidebar, click, close sidebar. I preferred having those buttons in the top bar.
The new design is pretty cool, this is just one user’s $.02 on one piece of the design.
It is good incentive to learn the keyboard shortcuts though!