Thanks to everyone's very helpful advice I've now got CM10.2 running on my SGS3. It's great! Much better and even though it's a nightly, I've not noticed any issues yet.
It didn't restore my contacts etc from the google account stuff, so ended up restoring my Touchwiz CWM backup and backing up all contacts/texts etc with Super Backup then flashing CM again. Worked a treat 2nd time around. Don't think I'll go back to touchwiz unless I find some absolutely glaring issue with this.
Thanks to everyone's very helpful advice I've now got CM10.2 running on my SGS3. It's great! Much better and even though it's a nightly, I've not noticed any issues yet.
It didn't restore my contacts etc from the google account stuff, so ended up restoring my Touchwiz CWM backup and backing up all contacts/texts etc with Super Backup then flashing CM again. Worked a treat 2nd time around. Don't think I'll go back to touchwiz unless I find some absolutely glaring issue with this.