Since you have it set up you can turn on the email portion of that account and remove the standard iOS Gmail account you've been using.ġ- As of iOS 7, a standard iOS Gmail account profile supports Contacts, so it now syncs Contacts (and Calendar) to Gmail with no workarounds.
I don't know of any reason you'd 'lose' email by using Exchange for a Gmail account, it always seemed to work fine for me.
If there's not a concern of emails being lost, then using exchange might be a fix for me. I only use exchange for calendar items and contacts. If I remember correctly, I don't use exchange for emails for fear of losing my emails to the device.
