If you were paying any attention to the tech, scanlines have been addressed and they have been deemed normal by Acer and also will be by Asus in time. It took Acer 3 months to confirm after we found the issue on the first week.
From Acer Perdator forums: http://community.acer.com/t5/Predator-Monitors/MULTIPLE-Problems-with-New-X34/td-p/390434/page/83
In regards to the scanline issue, I have been provided with an update. Scanlines are an effect caused by rapidly changing refresh rate. Variations in the refresh rate create an increased holding time that results in the accumulation of an electrical charge. When this charge is released, it causes small variations in the frame that result in faint horizontal lines.
We certainly appreciate everyone’s patience and the feedback that has been provided by many of you. Unfortunately, this is a side effect for cutting edge technology and while there is not a fix to be applied, we will continue to make efforts to minimize and eliminate these types of limitations in future releases.