The Libraries tab is more attractive than the Quick Load menu, but Quick Load allows me to better organize my libraries in a way that makes sense to me. If there is a Kontakt 6 in the works, I think a good solution would be to be able to hit a "library" button that expands all of the Kontakt Player compatible libraries into a large, square screen so you can see a dozen or more at a time and then make that scrollable. Also, being able to classify the libraries based on type (such as orchestral, synth, rock), or by developer and then choose a filter to display only those of your choosing would be a great addition.
Lastly, when trying to drag one of the libraries to a new position in the libraries tab, why in the world does it take a decade to scroll through the list? They really need to fix that! Haha!