I'm on my Early 2008 MBP connected via vpn to my clients system. No problems for me until i start opening multiple apps like windows, excel, and chrome. My computer lags will start lagging at that point. I have a 4gb memory and a 7200 rpm drive as well. Still waiting for my ultimate and wondering if anyone else is in my line of work. Anyone using their computer to run windows for reporting, spreadsheets, or connecting to an ERP systems etc?