The decision of whether or not to update iTunes is always a wary one for me.
On the one hand, it is possible they are patching essential security bugs that are leaving one or more of my devices vulnerable.
On the other, it is likely that the update will include at the very least a gratuitous and confusing user interface change, and at most will be another transformation in the functioning of the whole program. I don’t want to need to learn new software every time Apple decides to mix things up again, and they have an unfortunate habit of eliminating good features and introducing deliberately frustrating ones.
I don’t find the new version too difficult. I like the new interface much better.
The update seems to have broken my ability to buy anything from the iTunes Store. Instead of being able to make a purchase, I end up in an infinite loop where it says I must enter my password to update my billing information, then returns me to the same screen after I enter it.
This situation persists despite attempts to update my billing information (and change my password) through the Apple website.