Hello, I have a Macbook 2 GHz Intel Core 2 Duo with 1Go 667 MHz and i'm about to change the internal drive for a WESTERN SCORPIO 640GB SATA 150MB/S 2.5IN LP 5400RPM 8MB. So i'm wondering if i should reinstall the original OS (10.4.8) which i was using until now, or if i should buy and instal the latest Snow Leopard OS. I'm just a bit worried that the new OS will be heavier so slower for my 2 years old laptop. what do you think is best for this machine? I'm mostly working with music, Ableton Live, Logic Pro and stuff like that, and a bit of photoshop. thank you so much for any advice.