I have been using Mura 6 for some time and it is a huge improvement over Mura 5.6. The new GUI in 6 is a lot easier to use. The best part is the the organization of content items. The organization of the tabs and what items are in each tab has allowed for some easy customization for Content Administrators. Having only a few items in the Basic tab is a life saver.
Mura 6.1 (or what ever they may call it) is even better. The Quick upload feature and the quick upload with images is a huge improvement in that area. I can't wait to see what BlueRiver comes up with next!