Setting up gmail (exchange vs gmail) ?

[Markdf]

I'm puzzled as to what the difference is between setting up the native iOS mail app to use Exchange for my gmail account versus choosing the built-in Gmail account type. I'm interested in some of the new features that Google Sync released in the last day, but I assume I need to have my mail set up to go over the Exchange account type instead of Gmail (because all of Google's instructions reference using Exchange).

I currently have my mail set up through the Gmail account type, and my calendar and accounts set up through Exchange. Should I move my mail to Exchange also?

Is this just two ways of doing the exact thing? Or two ways to do slightly different things?

Thanks.