As we know manufacturers need to make a profit, hence they will often make material selections based on cost. Many believe the lens mount on Sony cameras is such an example.
Also some suggest the Sony (supplied) variant suffers from light leaks, which is of particular concern for those of us who take very long exposures.
So, once again, Fotodiox to the rescue: http://goo.gl/EaYFdo
Bottom line: from my perspective the simple conversion looks good and appears to do the job, ie lenses, especially large/heavy ones, appear to be more robustly connected to the the A6000 body.