I decided to switch to Ubuntu, at last. And I'm definitely happy for the choice: smooth looking feel, decent speed and big selection of applications.
Just one “down” point: I spent a whole weekend to install it! Not bad, for a distribution said to be “easy on”… After an afternoon reading here, not finding any useful suggestion for my case, I found the solution.
For me (and my Dell Inspiron 5150) the alternate cd worked. So, just forget the install/live cd and go for the alternate: there are no differences, a part from the fact that you'll have to forget the graphical istaller. hth.