they both use sony sensor technology, which has better performance regarding to noise.Adalbert wrote:ILCE 7RIV or GFX100 should produce comparable results.there is no other camera on the market with such sensor, so you cannot make a fair comparison.
in germany (and I believe everywhere in the EU) all web stores are obliged to offer a refund option with no questions asked.do you know anybody who can offer such service?buy the camera, try it, and if you are not happy with it, return it
I think B&H etc are pretty good in that regard too, but I would check first.
chris