In case y'all missed it the α7II will also be getting the goodness that is lossless ARW raw files via firmware update which is to be released on November 18th, 2015.
Fortunately, like the 7RII and 7SII this feature will be selectable, you won't have to commit to lossless raw after you update. That said, HDs are cheap, shoot the highest quality raw file you can. ;) Once the firmware update is made available I'll be shooting a side-by-side of lossy v. lossless raw for you to take a peek at.
The update will be available via Sony's support site.
I upgraded my A7Rii firmware so that I could shoot in 14 bit uncompressed RAW and was surprised to see my file size go from 42 to 85 MB. When I had my Nikon D800 I always used the 14bit uncompressed RAW and don't recall it even getting close to this size. I also have a Sony A7ii and will be interested to see how large the upgraded file is.