I saw what another reviewer had said about the outer sleeve having a 2011 date but the inner disc having a 2006 date. I thought perhaps it was a one off error so decided to order the 2011 'remastered' version.
Mine was exactly the same as the other reviewers so I decided to phone Sony Music and find out what was going on. I received an email back the same day telling me that the 2005/6 disc is exactly the same as the 2011 disc and there has been no remastering for the 2011 release. So the disc you buy was NOT remastered in 2011.
However the disc does contain all of ELO's best work and the sound quality is fine. If you love ELO then you will not be disappointed. The only alternative I considered was The Classic Albums Collection
but that was hugely expensive when compared to this greatest hits CD.
So the bottom line is that whether you order the 2005/6 version or the 2011 version you will be getting exactly the same CD, the new one only has a new card cover slip.