Hello, I change macbook pro almost every two years. In each case, it is very easy to use migration assistant to move all the stuffs from an old machine to a newer one that has more advanced hardware. (Haven't tried the other way around. Will it be as hassle free?) As for Windows, as far as I recall, even upgrading the RAM on the same machine caused problem. Why it is so easy to upgrade from one Mac to a newer Mac? What has Apple done to make it a very simple and hassle free task?