Mark L Audio is far better than Standard audio. But if you are not one of those who will pay 100s for headphones, you won't care.
Just for anyone else reading this and buying IS220D, avoid diesels. They come with lots of issues, not good for enviroment, eventually you will pay higher tax and insurance, diesel price per liter will go up, your car value will go down the drain fast, all sooner than later.
I think guys here should keep on preaching this like Pepsi ad.