Sony RAW is not fully RAW?

Yeah this probably isn't as big an issue as some people would think. Quality compression, especially something as little as 3:1 likely results in virtually no loss of usable information (though, as pointed out, can result in minor artifacting). For professional photographers, it's probably a deal-breaker as they can get a similarly priced nikon or canon without the compression.
As Fader stated, RED, ARRI and others utilize lossy compression, but still provide great results in post (granted these are cinema cameras).
If as a user you start noticing the things mentioned in the article, you may want to change systems, but for a large portion of us, ~3:1 (in fact it's not quite that high I think) will be a great size/quality compromise.
The best part of the article was the author surmising that Sony isn't quite the professional photography company canon and nikon are... and he's right. The a7 series probably sits near 7D with all things considered (no not exactly the same, but professional use-wise, close... the a7r maybe sits between a 7d and 5d) so until they release something like the 1D, which is 2 steps above a 7d for all intents and purposes, Sony, and we, probably shouldn't consider them in the same league.

edit: on the bright side if this type of information gains enough traction, you could be looking at some class-action against sony. nvidia's recent troubles with the gtx970 should have companies on edge a bit when it comes to exaggerating claims. sony really shouldnt be touting it as 14-bit raw if the saved image is less, even if it starts out at 14.
 
RAW doesn't mean uncompressed, it means not debayered and without any color transformations. Storing RAW information in log form is a good idea, if you ask me: there's no point in keeping the original linear data, it's just not useful. And adding some mild compression on top of that... well, it depends on your needs, but I wouldn't expect any issues in practical terms.
 
In reality I have never run into a situation where compression artifacts were present in A7s Raw files. Storing things with a log gamma curve is a really good way to "compress" visual information since our eyes cant discern the differences in very bright objects as we can with very dark objects.

Think about it this way: Many people clamor to deliver their footage in ProRes, which is also a visually lossy codec. At the highest data rates, ProRes is about a 4:1 reduction in size from uncompressed, and does it by throwing away information that isn't significant to your eyes. This is a broadcast standard and people don't complain about it when they shoot a test that can intentionally break ProRes.
 
There is an amazing article about Log gamma vs Linear images on Pro Video coalition:

http://provideocoalition.com/aadams/story/log-vs.-raw-the-simple-version

The big takeaway is look at how little information you store with your shadow areas when you store your image linearly, with no compression :

Rg167gj.png
 
Hmm, I come from a stills world - we shoot stills on D800 and D810 bodies. On our second D800 we were having focusing issues - pixel peep 36 megapixels in the pupil and find the image soft - we struggled with it for a long while - we couldn't figure out what was wrong - Nikon Tech said camera and lenses were in spec, there was no back or front focusing, just not tack sharp. Turned off RAW "lossless" compression... never knew such a thing existed - solved our problem. Now, I don't think I'll have that problem with my new A7S at 1080p or even 4K, and I don't plan on using it for many brightly lit stills. but if you a pixel peeper, compression is compression - no matter how good.
 
There are different ways to compress an image, Nikon's may not be using the same method as Sony's.

I have never run into an issue with A7s images at 1:1 zoom where I said "wow if this file wasn't as compressed this photo would be better."
 
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