So I just picked up the i5 mbp 13. I was looking at buying COD4 from apple. You obviously can't return software, so I wanted to ask before I buy it. Will it be able to fun smoothly on my new mac. I won't be playing at high settings. I just don't want to buy it and then be disappointed with it, since I don't have a discrete card. Also would the i7 make any noticeable difference playing this?