I've turned the feature off because it further decreases the amount of space available to view my photos. With the default setup my photo only takes up 33% of my screen, which on a 14" laptop screen is far too small for photo editing.
Aggreed that the ribbon takes up extra space. It's definitely "blibgy," and I don't know how I feel about it. The "Oh, it's cute!" person in the house will certainly think it's great, though, even if the picture gets smaller.
how about a vertical ribbon?