The installer uses a lot of space just to show the name of the installation step. In a 1152x864 screen it is using 396 pixels wide, that's about 34% of the total. I think that we could put the text in the upper green stripe in order to not waste neither vertical nor horizontal space.
1152x864 was the resolution I used in VirtualBox (if I use a lower resolution it works only the text based interface), my netbook is only 1024x600, so the problem is more noticeable there. Even with the 1152x864 resolution, the text in some tabs is cut.
Another issue I'd like to comment is that there are two Release Notes in the performing installation step: one has the text in Spanish (selected language) and the other in English. I don't know if this is a bug or a feature...