Getting 4GB is good for the lifespan of the card. A card with 4 gigs of RAM or higher will not go obsolete as fast. It may not be a bottleneck for your system right now to have 2 gigs, but it very well could be soon.When you're looking for budget cards... 4gb of vram vs 2gb of vram is not the item that is going to throttle your performance. Just sayin.
I can vouch for that statement. It's fantastic!