I`d also go for the in house upgrade. If you dont mind doing the completely fresh installation then there`s no harm in trying the upgrade first.
If you use a separate /home partition then the upgrade is always a little less hassle data wise when doing a fresh installation. Backing anything up first shouldn`t be too much of a hassle either of course, if it aint backed up already that is....ahem.
If you`ve installed a whole heap of stuff from synaptic, which you`d like to restore after any fresh installation, then you can just save a text file with a list of all installed apps for re-installation on the new setup.
Code:
dpkg --get-selections > my_installed_apps
Will save a file called "my_installed_apps" in your home directory and after you copy it to your new installations home directory...
Code:
cat my_installed_apps | sudo dpkg --set-selections && sudo apt-get dselect-upgrade
...Will restore them all again, the ones needing restored anyway.
You should be able to do the same thing with Synaptic of course....
Synaptic: File >>> Save Markings As. Be sure to tick the "Save full state, not only changes" in the lower left......To restore, Read Markings.
Unless you`ve been on a mad one and installed half the stuff in the repositories then it shouldn`t really be an issue of course.