In their full review of the Sony RX1R II, WhatDigitalCamera.com's Callum McInerney-Riley describes how the full-frame compact stacks up, 

"As the RX1R II features the same 42.4-million-pixel Exmor R back-illuminated CMOS sensor as the Sony α7R II, we were expecting good results – and we were not disappointed. This sensor is class-leading, giving extremely good performance all round. The dynamic range is exceptional, giving over 13 stops of dynamic range and, importantly, retaining dynamic range rather well across the ISO range. Aided by the high-quality lens, the sensor can also resolve a large amount of detail right the way through the ISO range. The new variable optical low-pass filter system works well to combat moiré while not compromising much on loss of detail. Noise is well controlled, and I would comfortably shoot all day long between ISO 50 and ISO 6,400. Overall, the colour rendition is good, with bright and punchy colours in JPEGs that are true to the scene.

"Our tests reveal that the Sony RX1R II sensor is capable of capturing over 13 stops of dynamic range. This makes it one of the best full-frame cameras we have ever tested, and in practice it’s easy to see there’s a wealth of information in both shadows and highlights. It retains a respectable dynamic range right up to ISO 800, only dropping by just over a stop to 12.2EV. Thereafter, full-stop ISO increments drop in dynamic range by around 1 stop each, with ISO 16,00 achieving 11.2EV and ISO 12,800 recording 7.6EV."

Check out the full review at WhatDigitalCamera.com