I am thinking of purchasing a MBP 17. Right not I am using a MBA 13, which I left a MBP 15 for. While the MBA is wonderful machine, I find myself missing the larger screen size. My question is this: how well will a C2D processor hold up over time? Should I even look at these models or should is stick to only the i7's? I do not do too much that is processor heavy, but I want something that will last a while. Don't want it to be sluggish after only a year or so, especially with Mountain Lion coming soon. Any advice is appreciated.