I recently upgraded from Ubuntu 11.04 to 12.10 but the system is so slow that I am unable to download anything from the software centre.
It's a clean install on a 32 bit Intel Celeron desktop with a 2.4GHz CPU, 2GB RAM and 160GB drive.
Ubuntu 12.10 has been disastrous for me on my other, similar machine after 12.04 was pure bliss.
I am strongly contemplating downgrade to 12.04, unless somebody has a magic wand.