The Sony FS5 and PXW-X70 offer not just fantastic images and 4K functionality, but also flexible features including the ability to stream live footage straight from the camera, a feature that many freelance camera professionals and production companies specialising in live events would surely appreciate.
XAVC is a recording format introduced by Sony which can support 4K resolution at 60 frames per second. Colour sampling can be 4:2:0, 4:2:2 or 4:4:4 at 8-bits, 10-bits, or 12-bits. XAVC uses an MXF wrapper whereas the consumer version XAVC-S is an MPEG4 wrapper. XAVC allows for both intra frame and inter frame (long group of pictures) recording. If you are the sort of person who is turned on by phrases like MPEG4 wrapping, Sequence Parameter Set and flexible data payload you can download the technical white paper here.