Currently, I did another try to get around with Ubuntu. My motivation for this was: I already used a kind of app dock (Docky) in Linux Mint and I really like the Head Up Display (HUD) and the app dock of Ubuntu. So I thought, let's give Ubuntu another chance. Also a comfortable thing is the integration of web applications (first class citizens).
At the beginning I also had to swallow some bitter pills: Ubuntu is very chatty! That is, especially Unity's shopping lens submits every search in the search panel (at the very first version directly) to Amazon. So I needed to remove this search lens and also others that I do not like.
Next, I needed a serious file manager. Nautilus, the default file manager, seems to be for people who do not really want to deal with files. Very strange to call this program a file manager! So I installed Nemo, which is a mighty file manager from Linux Mint. From that point, Ubuntu showed up 2 error messages at every system start. Also, I could not control anymore what icons are displayed on the desktop (trash, user home, etc.). So Unity's integration with other file managers is not very well.
The HUD and the menu at the top were one motivation for me to give Ubuntu one more try. The problem is, with my Java IDE, Eclipse, the menus at the menu bar could not be opened. So it is unusable. That is very sad. I know there may be a workaround, but it was not my intension to reconfigure and modify the whole system in order to use it.
Last but not least, I want to tell something about the app dock of Unity, whose position is at the left margin by default. Visually, I like this dock. But, as I work with an external, second display, I expect the dock to don't prevent me from using two displays. Unfortunately, when I pull a window from one display to the other one, the window sticks with the dock. Every times, it is a real fight to get the window on the other side.
Maybe, there are some tricks ans optimizations. But I want to use an operating system and not to hack it. So bye bye Ubuntu, hello again Linux Mint.