Using the online interface has been frustrating to say the least, as getting access to edit the prezi itself has been intermittent as has saving. Consequently, I've wasted a lot of time trying to edit, only to have to repeat the process later because it didn't save.
Eventually I downloaded a trial of the desktop application, and while editing was easier, it still left a lot to be desired.
Sharing it turned out to be an issue, even though the presentation was made public and reusable in advance of the Seminar, it takes ages to download and people trying to access ti seem t have to have a prezi account, which surely defeats the purpose of making it public. A zip file to share didn't work either.
Even when they get access to it it takes ages to load / download, which doesn't reflect well on yours truly.
I guess I'm cured of Prezi for another couple of years.