I have a 2.2 C2D MacBook Pro 15" with 4GB ram and a 200GB 7200rpm hard drive. I have the itch to upgrade. Am I going to regret going for a 2.4/4GB/320@7200 combo? Is it worth the extra $445 for the 2.8? Is the 2.4 not going to feel like that big of a difference compared to my current computer? I mean, there's nothing really that my MBP can't do, it's just that I want the new one and I feel like I should go for the speed upgrade at the same time. But I don't want to spend the extra money if it's not a huge difference.