The main drawback I see every time KDE gets updated is that everything changes. Few weeks ago the main menu changed to a ugly one with too big icons... and no way to get back the old one. Today the taskbar reappeared with an "only icons" version. Once I changed the widget to the traditional one I just have too much text in taskbar items...
KDE is a constant fight between the user keeping things like he wants and the developers changing everything to a worse / uglier version.
