DAZ Studio 4.12 - 4GB Card VS 6GB Card

Six GB cards usually come with approximately1200 cuda cores, four GB cards usually come with approximately 900 cuda cores. Numbers don't lie, but is there really an appreciable advantage to buying a 6GB card instead of a 4 GB card with DAZ Studio? The price difference doesn't amount to very much, about $75, but money is money. Any thoughts? And thanks to all replies.