I have just purchased a 27" imac It is the lower end model with 3tb fusion drive, and I have order 32GB ram from elsewhere(as I tend to have a 3-4 vms running at a time). The delivery date is listed as January. I have a few concerns with the 660M driving the a Dell U2713HM (2560x1440) as well as the internal display. I don't play games on the mac and I only rarely do light video editing work. Is it worth me cancelling and reordering with the 675MX or 680MX?