I am finally upgrading from my first gen 24" iMac to a new 27". When the new one arrives, I'm curious as to how I will get my stuff from the old one to the new. I do have time machine working, is that the best way - just copy from the external drive? It's been almost 5 years since I got this one, but I seem to recall the setup program asking if you already have a Mac - does it transfer from the old to the new somehow? Thanks for any insight or suggestions.