Also, I'm only on day two of my shinny new iPad, but after I did the Exchange Gmail connect option, I didn't notice if all my Google calendars were available on the Calendar button inside the iPad Calendar app. However, after I setup the Google Gmail account with the Exchange Gmail connect option, I followed the next procedure and went to 'm.google.com' on my iPad and selected the Sync icon which brought up a list of 'Managed Devices' which had my iPad listed. So, I selected my iPad and that allowed me to add all of my other Google calendars, including shared and read only calendars, to sync with my iPad.
My question is, why isn't this available natively inside the iPad calendar app after setting up the Exchange Gmail connect option?
Anyway, this is especially useful since I subscribe to the NFL shared calendars for my favorite teams. The bonus is that it maintains the Google calendar colors in my iPad calendar which I didn't expect.