New MFT user should go Olympus or Panasonic body and why?

I am thinking of getting either E-PL5 or E-PM2 because of the new Sony sensor but also wish to know why people would choose Panasonic body

Getting GF5 doesn't make sense to me as I think it use the last generation 12 MP sensor.  Someone said the new GH3 also use Sony 16MP sensor but don't know if true

Basically I want to know why people would choose Panasonic body

Is it because they want to use Panasonic lens or the new 16 MP Panasonic body also use Sony sensor?

Thanks