Well, if IE11 is set to not have the tabs shown always, then as for screen size, there is very little difference with going full screen.
I like Nate's suggestion to minimize automatically to the 'show highlights' icon.
I hope Photosynth history will be a very poor indicator in general for future usage patterns. I hope to live to see Photosynth being in mainstream use.
My drive to start this topic is a feeling close to what Nate describes in his last paragraph. It depends on what is the aim, traditional creative and great photography or sharing todays real life scenery now and into the future.