Bug in Unity 4.6.2 with placing several canvas elements?

I just updated to 4.6.2 and opened my project. I have a MainCanvas in my Project which contains several child canvas elements. These were placed out of view in the editor and are only moved into the view when the player clicks somewhere.

When I opened my project after the update all my canvas elements were moved into the player view and the size was changed. I moved them back to "out of view" but then I reopened the project they were placed at the wrong place again.

 

I tried 4.6.1p4 but it mess up with my canvas menues the same strange way.

 

This is a known problem with nested canvases. However, I'm not really sure why people have them. Seems like they are mostly useful for scaling your UI, everything else looks like it should be done with game objects or panels.

 

English isn't my native language so please forgive me my question but do you need with nested canvas the fact, that I use a main canvas that contains other canvases or does it mean using canvas in general? Would it already help to remove the main canvas and have just several different canvases parallel to each other?