I have an older MBP Santa Rosa, 2.4 Ghz dual core 15" .. I bought it with the stock 160 gb 5400 rpm hard drive, I've been running around with a full hard drive for a while and the thing was painfully slow. I finally pulled the trigger and bought a 500 gb WD 7200 rpm scorpio black upgrade kit from OWC. I installed it last night and have a fresh install of OSX Snow Leopard ... it is the most AMAZING difference ... it boots quickly, it is amazingly fast compared to what it was before. I almost wish I splurged and got the SSD ... could only afford the 120 gb though if I did that ... How much faster would the SSD be compared to the WD 7200 rpm scorpio black?