Why did you choose a 13 or 15" MBP? I'm trying to decide between the 2.5ghz 13" MPB and the 2.8ghz 15" MBP. Will I notice much speed difference during normal business tasks, writing, drawing in Open Office, email, surfing and for viewing video online, multi-tasking/multi pages open. Or would both perform about the same? Screen size and dedicated graphics is nice on the 15" but its hard to get past the smaller size and weight of the 13" when you can always hook up to an external monitor... what to do?