Well,
Firstly let me explain you what Upgrade means and what Fresh Install means.
UPGRADE -
Upgrade means your system will be updated to the newest resources,applications,libraries,Kernel versions and will have the latest Patches to various software BUT your data that was there in your /home
folder will remain intact.
FRESH INSTALL-
Fresh install means your system will be updated to the newest resources,applications,libraries,Kernel versions and will have the latest Patches to various software BUT your data in /home
will be completely lost because fresh install is nothing but installing a new OS.
Now,about your doubt about broken packages in upgrades,
This problem generally occurs when you upgrade online using the UPGRADE TOOL.
One way to avoid this is to burn an ISO immage on to a CD/USB making it bootable and then UPGRADING instead of INSTALLING FRESH
When you boot the CD/USB you have created and click on INSTALL on the first screen,next you will get a screen asking for -
- REPLACE 11.10 WITH 12.04
- UPGRADE 11.10 to 12.04
- SOMETHINF ELSE
If you select the 2nd option,you will have the benefit of UPGRADING with very less risk of Broken Packages
Always remember to select to INSTALL 3rd PARTY SOFTWARE
and UPDATE DURING INSTALLING
when you start the install. This further reduces the risk of broken packages later.
I would recommend UPGRADE USING A LIVE CD over INTERNET UPGRADE or FRESH INSTALL
Needless to tell,backup all your data.
Hope the answer helps you.