The main use of the headphones will be for gaming. I am currently using the DT 990 Pro's with a Jotunheim but find the 990s uncomfortable. I have heard that the Sennheiser 600 series is known for comfort and large sound base. Is it worth spending a couple hundred more dollars for the 660S if my main use for them will be gaming? Or will I get similar performance from the 6XX's?