Guys! It should work for everyone! First it didn't work for me, but I've noticed that the problem is with quotation marks in added line:
Replace quotation marks from this line (in /etc/default/grub) with quotation marks that you type yourself. It has worked for me!
This worked for me aswell on my ASUS UL20a! I am very happy to see the community pull through with so much great info!