My Late 2006 15" MPB is running a little low on space and I would like to improve the performance a touch if possible. The stock HDD is 120GB 5400RPM. What are my options? Do I need to go with the 5400RPM? Or can I upgrade to a 7200RPM? More importantly, will bumping up to the 7200RPM do anything for me? I have been told that a faster HDD can help to improve performance. Thanks!