@Modern? I dont think so!:
The whole Office 2013 color scheme is a tragedy. Huge amounts of screen space wasted by bright white. 90% of some screens are just a wasteland of white screaming into your brain and giving you a headache. OWA2013 is the same way, and you are correct, there are many problems. Public Folders are broken, plain and simple. Shared mailboxes don't even work at all, so you can just throw that feature right out of your current plans. Even the OWA offline mode is a joke as it will only sync 20 folders and no more. If you look on the Technet forums you will see hundreds and hundreds of complaints about this same thing.
It's a cruel joke that is being played on us Exchange Administrators, that's for sure. Release products WAY before they are ready and spend the next year patching things up so we can finally have a RTM-capable experience.
Surely even the Microsoft team can see all the deficiencies in their product. Even with CU1.