I am usually not a fan of MS Office but I do think that the solution for the
slide notes display / editing in PowerPoint is far more usable than the solution
in Impress.
The need to switch to a different tab window for working on either the slide
_or_ the notes is hindering work: Often changes in one part affect or require
changes in the other part as well.
The notes view in Impress also implies either an almost unusable small display
of both slide and notes or the constant need of scrolling and zooming.
I therefore propose to redesign the notes view in Impress with the PowerPoint
solution as role model.