Does anyone know the specifics, or have a specific opinion, regarding the use of Cocktail or Mac Tune Up? I have the trial of Cocktail based on the recommendation from MacLIfe, but I see that my local Best Buy carries the Mac Tune Up application. There is a minimal price difference so I ask, what would you use, if any? I have a 2009 iMac purchased in July and want to keep things running smooth. I love this computer!!!