Well... the difference between the two was the size of the sensor, the size of the body, ergonomic, etc.
And the pro and cons can be found widely in the net, so don't ask this type of question again.
And I can predict TS next question,
1) what would the difference of sensor size brings about (or something to that effect)... the answer is... it will not bring too much effect on the IQ of the photo taken, sure noise control for smaller sensor will suffer a bit, but seriously the way to photography is not just base on how much or how little noise it is in a picture.
2) How about a small compact camera with bigger APS-C sensor when compare to a m4/3 sensor camera... Well again, the answer is... there will NOT be any difference unless you pixel peek. And like answer number 1... noise, sharpness and cleaniness are just a small part of the photography process... there are other things involve such as composition, skills and techniques.
So there.