To try to explain it better, say you have 10 libraries of planets from say Mextrees. Each comes with notes on how to install them. So if you install each library, you end up with 10 folders Yellow, each containing one library folder Green, so if you want to open a library, you open the yellow folder, then the green one.
My tip is using drag and drop, to move al the green library folders, into the ONE yellow folder, as shown in your example. So now when you want to open a library, you only have to open the one yellow folder, which contains al of the green folders, saving on clicks... I know it's not really much of workflow improvement, but when you want to view what items you have, when you have dozens of libraries, having to open a dozen yellow top folders, to then open each of the actually library folders, can get tiresome.
That said, I cannot wait to see a full tutorial on how this new library browser works, as so far I have added some small groups of plants, that I use in almost all my exteriors, which really helps. Otherwise I have to load in a huge file of plants, many of which I might not use, or I convert them all to V-ray proxies or I have to locate each one of them, on whatever drive they are stored on. So this very fast way of creating a library, buy loading all the objects into max, selecting them all and getting the library browser to generate the library, and thumbnails, is so much quicker.. and now if I want a particular plant, in my scene, from that small collection of plants I use most often, I just choose that library, choose the plant(s) job done
As for the rest, I am sure there are plenty of fixes and a few bugs to iron out, as we al know it is a beta, but so far, I have yet to encounter any problems serious enough to revert back to FP6