Hello good people of the Avast community 
I just saw that Avast 6 is now official and I was wondering if I should upgrade through the Avast 5 GUI or is it better to perform an Avast 5 uninstall and a fresh install of 6.
What do you think?
You can do any of the processes.
Try direct upgrading and, if anything fails, try an installation from scratch.
I did it through the program update feature and was very pleasantly surprised with no issues whatsoever