Hi guys, I'm going to buy a 13 inch mbp for my gf. BB offered the 2.3 mbp $100 cheaper than the 2.4. Looking at the specs, it looks the only difference are 2.3 vs 2.4 and 320gb vs 500gb. Since I will upgrade the hd (750 gb 7200 rpm) and memory (8gb RAM) by myself, the hard drive difference is a non factor. I think I know the answer already but will the difference between 2.3 vs 2.4 in processor will be noticeable? Are there any other difference beside the hard drive and processor which I missed?