I have this great external hard drive from Western Digital.  It rocks as a clean, highly-portable drive.  However, then it has this software that is supposed to help with synchronizing and protecting files.  The thing is miserable to work with as every time you make a selection in their UI, if the folder you are configuring is of any size, the UI freezes up like this:

Users expect that you make setting and configuration changes, *then* click the “go forth and do that” button and at that point expect to wait not before.  Great example of how not to design a UI.