EverydayGetaway wrote in post #16112522
Bashers of the 6D will constantly tell you that there's less than a stop of ISO improvement, but in actual editing of the RAW files that's just not true, I actually find it gives you much more than that. I've handled several high ISO files from a 5DII, they're definitely not as useable or easy to work with as my 6D's or my friends 5DIII files. The price difference is pretty much negligible... get the 6D.
Yea, I'd probably be one of those 'bashers' for most regular shooting, but even though I don't' have a 6D, from what I have seen it will be much much better for astrophotography and long, high ISO exposures.
As others have mentioned, it's not just the noise as we see in those tests that get posted, but the character of the noise and how it responds to NR. Long exposure shots create slightly different noise issues than simple high ISO 'portrait' shots. 5DII is not that impressive in that area and has a lot of large blotchy chroma noise.