By removing all the borders/bars, and other useful grouping elements, they've made the application feel cluttered -- too many unrelated things share the same z-

By removing all the borders/bars, and other useful grouping elements, they've made the application feel cluttered -- too many unrelated things share the same z-index. For example, the pinned panel titles, side panel buttons, inactive tabs, and toolbars are all on the same background. Considering how unrelated these things are in comparison to each other, I don't think they should share this same "zone". I'm not saying a design like that can't be done, but the only way I can think of making it work would involve much better use of the grid system and much better spacing than what they have in these pictures. Considering how limited they are for space though, I think they were just better off with the 2010 look.