Upgrade or install fresh ubuntu 9.10

"I normally just upgrade because I'm lazy.

However, one of the options you may be presented with during this upgrade is to upgrade from ext3 to ext4, with is the new default file system type in 9.10. If you have not backed up your data I would NOT elect to perform this as part of your upgrade. The notes on the Ubuntu site indicate that ""maximum performance will typically only be achieved on new filesystems, not on filesystems that have been upgraded from ext3""."