I just finished upgrading my i9020a from 4.0.3 to 4.0.4. Everything is working fine so far.
I did have an issue when upgrading from CWM. When it was verifying the files, it complained about Music2.apk. I had deleted this file from the system/app folder when I first installed ICS since I has installed CM Music app and wanted it to replace the default player.
Luckily I had a copy of the 4.0.3 full zip file, so I browsed into it, found the apk I needed, copied to SD card and moved it back into the right folder. Uninstalled the CM Music first. Make sure to match the Music2.apk permissions to the same as everything else in that folder. After a reboot, I confirmed that the Music app was back and shut down back to recovery. Once in recovery, it tried the update again and it all worked properly! Radio file didn't need to be reinstalled again, but I wouldn't mind a newer one since I'm currently running AUCKE1 cause nothing else seemed to work for me!
Hopefully 4.0.4 will have better battery life!
P.S. My wifi works too!