OS X :: Difference Between Restoring And Migration For New IMac

I ask this question as a new Apple user with a pretty rocky start. I'm on my second defective iMac (yellow tint, stuck pixel, smell, etc). Because of 2 defective iMacs in a row and another replacement in the near future, I now need to learn about how to transfer settings/data from one Apple to another most efficiently--if at all. I previously understood it would be best to simply not use Migration Assistant on a new iMac, even though as a new Apple user I really have little data history to transfer over. So with my next replacement, and hopefully the last, I would start from scratch with new application installs, OS settings, documents, etc. The logic as explained to me is that migrating would transfer over files I would not want on the new iMac. However, when I spoke to Applecare over the phone tonight, I was told that while I could Migrate, I should instead Restore all my settings/data from a Time Machine backup from this defective iMac to the new one. As I understand it from how he explained it: with Migration you will simply transfer your old data/settings on top of what exists on the new iMac, but with a Restore the new iMac will wipe out whatever is on it (is there anything to wipe out on a new iMac?) and then transfer your old data/settings. Is my understanding of those 2 terms, Migration and Restore, correct? And is Restoring the preferable thing to do in that it doesn't (or shouldn't?) bring over any unnecessary files into the new iMac and saves a great deal of time or should I still start completely from scratch?