Many of us our anxiously awaiting the 4.6K Blackmagic Ursa Mini and its 4.6K sensor. There has only been one release of sample footage from this sensor and not much actual analysis from people who have had time to play with the camera.
OneRiver Media Blog has had an opportunity to use this camera and their preliminary findings are promising:
The highlight retention is stunningly gorgeous with subtle, silky smooth roll-off that any cinematographer would appreciate.
Clean shadow retention? Gorgeous.
Skin tone rendition? Beautiful.
Overall color fidelity? Immersive and accurate.
Detail? Crisp and clean.
See their article for more.