What I like about the first mockup is that it's less cluttered at the top, also the use of a logo/pic for the add-on instead of the user avatar IMO looked better and made more sense. But other than that, the new layout makes more sense.
One suggestion to reduce the clutter at the top: remove the 'post resource update' button at the top right. It's already to the right below "Resource tools" which is enough. No need to clutter the top with yet another button. Furthermore a 'call to action' button is not required for resource updates as they will come naturally.