Originally posted by kenafein I feel that the size advantage is huge. The NEX 6 is the perfect size for a camera, in my opinion. Also, while it is hard to make a direct comparison of lens quality, most of the NEX primes outperform the LTDs on DxO tests. Unfortunately they have only tested them on a 24mp sensor, but they would likely still test better. We all know there is more to a lense than the DxO score, but you can't make an assertion that the Pentax lenses are better.
Without regard to lens quality, there are more advantages besides size, IMO. I was instantly impressed with the size and quality of the viewfinder on the NEX6 I handled at the store. Focus peaking on a live image is something I'll use a lot. Live histograms and live renditions of exposure compensation will be important. Even the placement of the viewfinder at the camera's edge is something I find attractive.
I'm pretty sure my next camera will be a mirrorless APSC, most likely the NEX7 or whatever replaces it. As small as the Pentax K30 is, I still find it getting left at home a lot. I've been assured that a NEX and 20mm pancake prime are likely to fit into a pocket, and my pockets always go with me. :-)