Evidence of Sony censor?

I've worked with a lot of images from the GH2 and the EM5 and they look nothing alike. In particular, the GH2 has a blotchy high ISO noise pattern that causes color shifts on the chroma side. (Look at RAWs without NR.) The EM5 noise pattern is totally different. If you compare ISO 6400 shots of the two cameras, the EM5's color won't drift towards purple the way the GH2 will.

The other bit is that the GH2 seems to clip highlights much more harshly than the EM5. I haven't much time looking at this effect in detail though. (I'm not exactly sure if it's actually different clipping behavior, or wider dynamic range with pushed processing leads to less clipping in the EM5.)

My question is mainly: if it's just a question of improved ADCs, why does the G5 look so much worse than the 4th gen PENs?