I purchasrd the 4 GB system for myself this year..I quickly realized that the space was not adequite..Microsoft wants $120 for a 320 GB hard drive..I did some research and purchased a 320 GB drive from Newegg for about $65..it took about 30 seconds to install..
That is my experiance,... and my two cents..... You must deceide what is best for you..Happy gaming....