The NEX-7 has issues with several M lenses 35mm and wider. I haven't seen the Skopar used on the NEX-7, but I have seen it used on the NEX-5, and there is corner smearing, so don't expect it to be great for landscapes (same with the Nokton 35/1.4.) I'm not sure if the Skopar has any color shift on the NEX-7, but the ZM 35/2, ZM 35/2.8, 35 Summicron ASPH and 35 Summliux ASPH all have color shift to varying degrees.
After owning a total of 5 different 35mm rangefinder lenses on NEX, I tried the new, cheapie Sigma 30/2.8 on the NEX-7, and it pretty much blows everything away in terms of detail across the frame at all apertures, and I find the rendering suitable. Sigma went with a highly telecentric design with this lens, so the NEX-7's sensor doesn't create issues as you go towards the edges. It's earned the nickname "Sigmarit" on other forums, and is a no-brainer for $199.