Is paying the extra £150 to go from a 120BG 5400rpm HDD to a 160GB 7200rpm HDD worth it? How much faster is it? And is the difference greatly notable? And what part of the performance will I notice the effect in the most? The reason I ask is because I do Photography and will have thousands if not tens of thousands of photos stored on my Macbook, will I notice the HDD speed difference and is it justifiable paying that £150 extra for it or would I be better just looking for an external HDD? Also is it worth taking the 200GB 4200rpm drive in to consideration due to the larger capacity?