A couple of bugs/issues I have noticed:
1). The screen on the search results page is around 6000 pixels wide.
The horizontal scroll bar goes a long way to get to the vertical scroll bar in the app.
2). Only one Top level group is allowed.
All other groups created are below the first level group.
(Not sure if this is a bug or a feature).
<EDIT> I see groups can be nested many levels deep, so this is really not too much of an issue, as long as the top level name is kept generic in name </EDIT>
3). Custom user created fields are not accessible in Report Writer to create custom reports.