This article could not be more inaccurate.
First of all, the original 3g sensor was better than the 3.5g, and the 4g is significantly worse than both. The optical artchitecture they use in these mice is all very similar and not really good for anything over 1800 DPI. So why are the opticals 6000 DPI now you ask? They cranked the DPI through the roof solely as a marketing gimmick on the 4g, which introduces lots of jitter and unstable cursor movement, then they add tons of excessive smoothing and post process correction to try and fix it.
You know in some video games in the option screen when you see an option that says "Smooth Cursor Movement"? The setting that virtually no video game player on earth ever wants to have turned on? Well that's the problem with the 4g sensor. It's the equivalent of building that option into the mouse and forcing you to have it always turned on. It's a complete marketing scam and these new outrageous DPI mice are not valid for gaming at all.
Razer probably hired the guy to write this article now that the truth about these new high DPI scam mice is getting out.
The Avago 4000 DPI optical firmware is also highly affected by similar smoothing, while the 3500 DPI firmware version wasn't. I just wrote a thread about that the other day:
Also, click the link in my sig for correct BIOS and Windows settings for mouse response.