I'm a newcomer, so I don't have experience with the old panel to compare with, but I love the layout. It's really clean, easy to navigate, and mobile friendly!
I like that the design is understated when I am working in public places. I personally love the amount of white space and font size, however I can see that others are having problems with it when working in public. Perhaps a mechanism to control font sizes with little A- / A+ buttons?
It's fairly easy to use, although I had difficulty publishing my story after previewing it (it said 'status: draft' and I couldn't find the 'publish' button until I previewed it again).
It would also be great to be able to search for Authors to follow from the 'Following' interface like you can with the 'Favourites' section.
I'd love to see this design style applied site wide, especially in regards to responsive design, font size and navigation!