Hi everyone, I searched around the forum so sorry if this is a repeat! I have a late 2007 MBP with 4GB of RAM running Mountain Lion. Has anyone heard what I should expect in terms of speed if I upgrade to Mavericks? Typically when updating to a newer OS you get new features but at the expense of performance. But, Apple is claiming many performance enhancements in Mavericks. Has anyone installed Mavericks on an older MBP who can comment? Thanks! Larry.