I think what you'll find is that most of the responders in this thread who claim that APS-C still has the edge actually own DSLRs and MFT cameras .IQ on my pen is just good as most any APS DSLR (even up to 1600 ISO). Anyone who says their SLR is far superior hasn't tried a Pen. And the M14-42 Std lens that I'm using is excellent. Though not up to my 12-60 for sharpness but close. I feel the some SLR users are starting to feel threatened by the PEN/GF cameras..they shouldnt. They should buy one and use it for travel or the perfect back up.
Whereas most of the pundits who believe that the two are equal usually don't.
I don't think DSLRs are "far" superior. They're close. But still ahead.