I got a new MacBook 2.4 Ghz with stock 2 GB of RAM. Prior to that I had a 3-year old MacBook with 1.8 Ghz processor, 2 GB of RAM and an upgraded 7200 RPM hard drive. What has really surprised (and disappointed me) is that my old 1.8 Ghz MacBook was much snappier and more responsive than my new one, despite a much slower processor. I'm not doing anything intensive. Just launching apps like Safari, Mail, iCal, etc. This morning I opened up Numbers, and it took a full 10-15 seconds to get to the splash screen. Can't be the memory, because it also had 2 GB. I suppose it could be the 7200 RPM hard drive, but I wouldn't have thought it would make such a big difference. Any other possibilities come to mind? I've run system maintenance with Cocktail and rebuilt the directory using DiskWarrior (shouldn't be necessary with a new computer), and nothing has helped. I'm considering getting a 7200 RPM hard drive, since they're pretty cheap. Or upgrading to 4 GB RAM. Any sense of what might give me the bigger improvement in responsiveness?