There is a lot of hype and talk nowadays about the great IQ from M43 and that it is as good as what you can get from 43.
While in general this can be true I found that if you compare top of the line 43 IQ (resulting from E5 with Pro 43 glass) to IQ from M43 (GH2, EP3 with according M43 glass) 43 still wins clearly! I recently made some comparisons between RAW images from all the mentioned cameras and there was a clear IQ advantage from 43.
This might change if there will be Pro grade M43 glass available, but currently we are far away from that. No misunderstandings please - I value the compactness of M43 compared to 43 but end of the day IQ is still far better from Pro Grade 43.