I have a 17" MBP mid-2010. It has worked beautifully for the 3 years I have had it, until I upgraded to Mavericks. Now my MBP is extremely sluggish and just doesn't respond like it used to. The specs are: Processor 2.66 GHz Intel Core i7, 8 GB memory. I added an aftermarket SSD drive, so this computer should not be as sluggish as it is. I am at a loss as to what is causing this. At instance of this would be typing and as I type there is a delay before it appears on the screen. This is particularly maddening!